US AIR FORCE

INSTITUTE FOR NATIONAL SECURITY STUDIES

USAF ACADEMY, COLORADO

INSS OCCASIONAL PAPER

SEPTEMBER 2013 69

Justin V. Anderson and Jeffrey A. Larsen

with

Polly M. Holdorf

Extended Deterrence 

and Allied Assurance: 

Key Concepts and Current 

Challenges for U.S. Policy
Extended Deterrence and Allied Assurance: 

Key Concepts and Current Challenges for 

U.S. Policy

Justin V. Anderson

and

Jeffrey A. Larsen

with

Polly M. Holdorf

INSS Occasional Paper 69

September 2013

USAF Institute for National Security Studies

USAF Academy, Colorado
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The views expressed in this paper are those of the authors and do not 

necessarily reflect the official policy or position of the Department of the 

Air Force, the Department of Defense, or the US Government. The paper is 

approved for public release; distribution is unlimited. 

This report was originally prepared by SAIC for the U.S. Government. It is 

published with permission of the sponsoring agencies.

Study completed February 2013.
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ABOUT THE AUTHORS

Justin V. Anderson is a Senior National Security Policy Analyst with SAIC 

in Arlington, VA, providing contract support to government clients on 

nuclear arms control, deterrence, and WMD proliferation issues. He is 

editor of the Headquarters Air Force, Strategic Plans and Policy (AF/A5XP) 

“emerging issues” report series and lead analyst for the portfolio’s nuclear 

arms control analyses. His past experience includes serving as Senior Editor 

of the DoD Law of War Manual and providing analysis to the DTRA, OSD 

AT&L Office of Treaty Compliance, and Missile Defense Agency. Dr. 

Anderson received his PhD in war studies from King’s College London. 

Jeffrey A. Larsen is a Senior Scientist with Science Applications 

International Corporation (SAIC) in Colorado Springs, CO. Dr. Larsen was 

the first Director of AF/INSS and continues to provide contract support to 

the Institute. He also works with Headquarters US Air Force, the Defense 

Threat Reduction Agency (DTRA), and US Strategic Command. He is 

widely published in the fields of national security, nuclear policy, arms 

control, NATO policy, and the role of airpower in recent conflicts. A retired 

Air Force Lt Colonel, Dr. Larsen earned his PhD in politics from Princeton 

University. 

Polly M. Holdorf (Annotated Bibliography) is a National Security Analyst 

with Toeroek Associates, Inc. at the US Air Force Academy where she 

provides on-site analysis, research and editorial support to INSS. Ms. 

Holdorf was a participant in the 2010 Project on Nuclear Issues (PONI) 

Nuclear Scholars Initiative program. Previously Ms. Holdorf worked as a 

Field Representative in Colorado’s 5th Congressional District. Ms. Holdorf 

received her M.A. in international security from the Josef Korbel School of 

International Studies, University of Denver.
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TABLE OF CONTENTS

FOREWORD ix

EXECUTIVE SUMMARY xi

PART 1: INTRODUCTION 1

PART 2: DEFINITIONS AND FRAMEWORK 3

Definitions 3

Deterrence 3

Central Deterrence 4

Extended Deterrence 5

Assurance 5

Conceptual Framework for Extended Deterrence and Assurance 7

Political Resolve 9

Political-Military Support 18

Military Capability 24

Tailoring Extended Deterrence and Assurance Strategies 31

PART 3: DETERRENCE, EXTENDED DETERRENCE, AND ALLIED ASSURANCE 

FROM THE COLD WAR TO THE WAR ON TERROR (1945-2008) 33

Continuity and Change in U.S. Deterrence, Extended Deterrence, and 

Assurance Concepts 33

Cold War Deterrence 33

Post-Cold War Deterrence, Extended Deterrence, and Allied Assurance 55

Extended Deterrence and Allied Assurance 64

PART 4: CONTINUITY AND CHANGE IN U.S. EXTENDED DETERRENCE AND 

ASSURANCE POLICIES, STRATEGIES, AND FORCES (1945-2008) 65

Policies 65

Strategies 66

Cold War 66

Post-Cold War 68

Forces 70

Conventional forces 70

Nuclear Forces 71

Missile Defenses 71

Challenges to U.S. Efforts to Extend Deterrence and Provide Assurance 73

Doubts about the United States’ Political Resolve (“de Gaulle’s Doubts”) 74

Questions Regarding U.S. Military Capabilities (A ‘Leaky’ U.S. 

Umbrella?) 75

The “Healy Theorem:” The Perpetual Challenge of Correctly Tailoring 

Extended Deterrence and Assurance Strategies 76

Defending the Status Quo Ante: Allied Resistance to Changes in 

Extended Deterrence or Assurance Strategies 79
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PART 5: CURRENT U.S. EXTENDED DETERRENCE AND ASSURANCE 

POLICIES, STRATEGIES, AND FORCES 83

Obama Administration Extended Deterrence and Assurance Policies 83

Obama Administration Views on Geopolitics, National Security, and 

21st Century Deterrence 83

Obama Administration Extended Deterrence and Assurance Strategies 92

Extended Deterrence Strategies 92

Extended Deterrence: Military Force Requirements 95

Allied Assurance Strategies 98

Allied Assurance: Military Force Requirements 101

Current Issues and Challenges for U.S. Extended Deterrence and Assurance 

Strategies 102

The Broad Requirement of 21st Century Deterrence 104

Tailoring Assurance and Extended Deterrence 109

Increasing Allied Involvement in Deterrence and Defense Strategies 110

Focusing Extended Deterrence Strategies on Risk Taking States 112

Reducing Reliance on Nuclear Forces and Increasing the Role of Missile 

Defenses 116

PART 6: REGIONAL ISSUES 121

Regional Security Architectures 121

East Asia 121

Extended Deterrence 121

Assurance 125

Key Issues for Asian-Pacific Extended Deterrence and Assurance 

Strategies 129

Middle East 130

Extended Deterrence 130

Assurance 133

Key Issues for Middle East Extended Deterrence and Assurance 

Strategies 135

NATO/Europe 136

Extended Deterrence 136

Assurance 139

Key Issues for NATO Extended Deterrence and Assurance Strategies 140

PART 7: CONCLUSION 145

APPENDIX: EXTENDED DETERRENCE LITERATURE REVIEW 149

NOTES 161
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FOREWORD

We are pleased to publish this sixty-ninth volume in the Occasional 

Paper series of the United States Air Force Institute for National Security 

Studies (INSS). This study was sponsored and released by the United States 

Government and conducted by a team from the Science Applications 

International Corporation (SAIC). While this research was not sponsored by 

INSS, it is both compatible with our efforts and objectives, and its authors 

are associated with INSS in other aspects of their positions. It is published 

here to support the strategic education of national security professionals in 

the Air Force and across the government. 

INSS Occasional Papers are currently published electronically and 

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national security education and to inform the security policy debate. 

INSS found this study to be particularly significant because of its 

focus on an important topic that has been receiving attention from across the 

United States and allied governments over the past four to five years, yet it is 

little understood outside of the government strategic policy communities. 

INSS completed its own three-year series of workshops and studies on this 

topic and the current strategic implications changes here are presenting to 

the US Air Force. We hope that the study published here provides deeper 

and broader understanding, and that it contributes to the ongoing discussion 

in this policy arena.

About the Institute

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USAF Academy. The mission of the Institute is “to promote national 

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INSS coordinates and focuses outside thinking in various disciplines and 

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To that end, the Institute develops topics, selects researchers from within the 

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dissemination of information to a wide range of private and government 

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EXECUTIVE SUMMARY

The United States provides extended deterrence and assurance 

guarantees in vital strategic regions across the globe to protect U.S. allies 

and friends from intimidation, coercion, or attack. These guarantees 

currently play a central role in maintaining regional stability and strongly 

influence the national security strategies of both allies and adversaries. 

From the Asia-Pacific to Europe, however, these guarantees – and the 

military strategies and capabilities that support them – are showing signs of 

strain. Decisions and actions in the near-term are critically important to 

determining whether these commitments remain firm or begin to crack under 

the pressure of adversary capabilities, allied anxieties, and resource 

constraints. 

This paper provides a conceptual framework for the strategic 

concepts of extended deterrence and allied assurance and an overview of the 

key issues and current challenges faced by the U.S. strategists and planners 

responsible for developing and implementing these concepts across the 

globe.

 

Deterrence and Extended Deterrence

The strategic concept of deterrence involves the protection of the 

U.S. homeland, its national interests, and its freedom of action by 

convincing a potential adversary that any attempt to attack the United States 

will prompt a response imposing unacceptable costs against it and/or 

denying the realization of the objectives it seeks. Deterrence exists in the 

eye of the beholder; it is an effort to persuade a foreign actor at the 

psychological level that the United States has both the military capability 

and the political resolve to carry out its threatened response. The effective 

exercise of deterrence strategies prevents adversaries from implementing 

courses of action detrimental to U.S. national security. 

The United States has long recognized, however, that its own 

security is closely linked with the safety and security of its allies around the 

world. As a result, in addition to taking steps to deter attacks against the 

United States, U.S. leaders have also sought to protect America’s friends by 

extending deterrence against their potential adversaries. This extension of 

deterrence over U.S. allies and partners has often led to the use of an 

“umbrella” or “shield” analogy to describe policies or strategies protecting 

U.S. allies from hostile third parties. 

A U.S. extended deterrence guarantee to a foreign ally or partner is 

likely to significantly impact the plans and strategies of that ally’s enemies, 

who are forced to calculate the potential costs of the United States 

intervening if they precipitate a crisis or conflict. The corollary to the U.S. 

extension of deterrence against these adversaries is the assurance such a 

commitment brings to the ally. In addition to strengthening ties between the 
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United States and the ally in question, an extended deterrence guarantee can 

also have the ancillary effect of contributing to U.S. nonproliferation goals 

by convincing an allied government it does not need to develop weapons of 

mass destruction (WMD) to counter an adversary equipped with nuclear, 

biological, or chemical weapons. By simultaneously implementing 

assurance strategies focused on allies and extended deterrence strategies 

focused on potential adversaries, the United States acts as the key security 

provider and central power broker in important regions around the world, 

ensuring its policies serve as a bulwark against geopolitical instability and 

armed conflict. 

The effectiveness of these strategies relies on the careful 

orchestration of the full spectrum of geopolitical and military resources 

available to the United States. Simultaneously assuring allies and deterring 

their enemies requires nimble diplomacy, strong relationships with allied 

political and military leaders, well-equipped armed forces, and the consistent 

demonstration of the United States’ steadfast commitment to accept risks 

and, if necessary, bear costs, in order to protect its allies across the globe. 

Extended deterrence and assurance strategies thus represent politicalmilitary frameworks whose maintenance depends on the close coordination 

of decision-makers, diplomats, intelligence officials, defense strategists, and 

military planners. The scope of the task reflects the central importance of 

these strategies to international peace and security, and leads to constant 

scrutiny by foreign parties – both adversary and allied – of U.S. extended 

deterrence and assurance commitments in order to determine whether they 

show any signs of weakness or fatigue. 

Bedrock Security Commitments and Flexible Strategies

Allies placing their trust in U.S. defense guarantees must believe the 

United States commitment to their security will not waver; at the same time, 

the strategies and plans that implement these commitments must flexibly 

adapt to geopolitical change and evolving regional security environments. 

During the Cold War, strategies such as “massive retaliation” 

initially relied heavily on nuclear forces to counter the numerical imbalance 

in conventional forces favoring the Soviet Union and the Warsaw Pact. The 

United States and its allies, however, wrestled with the implications of 

threatening the Soviet Bloc with Armageddon over conventional 

provocations or attacks, and throughout the Cold War U.S. decision-makers 

and strategists attempted to find the balance between credible and incredible 

threats, particularly as Moscow developed an increasingly capable nuclear 

arsenal of its own. Would the United States be willing to sacrifice New 

York in order to protect Hamburg? And would Washington devote enough 

military resources to extend an effective defensive shield over its far-flung 

allies? These questions bedeviled U.S.-allied relations for decades, but from 

the 1960s onward they also sharpened U.S. efforts to develop a family of 
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“flexible response” extended deterrence strategies. By using a combination 

of conventional and nuclear forces, U.S. strategists and planners sought to 

frustrate Soviet efforts to coerce allies or engage in brinkmanship by 

threatening to impose costs or deny benefits at specific flashpoints or on key 

battlefields.

The end of the Cold War replaced the challenge of extending 

deterrence against a global superpower with the challenge of extending 

deterrence against a host of potential adversaries, to include peer and nearpeer competitors, regional “states of concern,” and non-state actors. The 

United States also sought to assure a broader range of allies, with former 

Warsaw Pact adversaries joining NATO, and states in the Middle East and 

Asia-Pacific seeking to establish or strengthen security ties with the world’s 

sole superpower. While the development of increasingly effective missile 

defense systems granted the United States a new deterrence by denial 

capability, the expanding number of actors involved in extended deterrence 

and assurance strategies – to include potential adversaries with very different 

views on nuclear forces from those held by the Cold War superpowers –

added new variables to the calculations of U.S. strategists and planners. 

Obama Administration Extended Deterrence Policy

The Obama administration has sought to re-examine and revise U.S. 

deterrence strategies and concepts for the 21st century. Finding previous 

U.S. deterrence thinking too focused on Cold War concepts centered on 

nuclear forces, President Obama and his national security team have sought 

to strike a balance between reducing the U.S. nuclear arsenal and 

maintaining the ability to defend the United States and its allies from nuclear 

threats. In order to protect U.S. allies and partners from actors armed with 

nuclear weapons and/or other forms of WMD, the administration has sought 

to develop strategies featuring a combination of nuclear, missile defense, 

and conventional forces, with the latter two assuming a larger role relative to 

the former. The administration’s views on extended deterrence and 

assurance are also shaped by a desire to establish “strategic stability” 

relationships with the Russian Federation and People’s Republic of China. 

As a result, the administration has focused its development of these 

strategies on two sets of challenges: threats posed by regional “risk taker” 

states such as Iran and North Korea; and efforts by a number of foreign 

actors to develop anti-access/area denial (A2/AD) strategies focused on 

countering the speed, flexibility, and global reach of U.S. military forces. 

The first challenge has led the administration to question the utility of past 

U.S. deterrence strategies due to Tehran and Pyongyang’s willingness to 

threaten the United States and its allies despite the ability of the U.S. 

military to exact heavy costs against either government in the event of a 

conflict. The second has prompted an interest in extending deterrence 

beyond allied borders to the “global commons,” with the United States 
xiv

committed to defending free access to international waters, outer space, and 

cyber space. 

Current Issues, Challenges, and Regional Considerations

These changes to U.S. extended deterrence and assurance concepts, 

along with recent geopolitical developments, have raised a number of issues 

and questions for U.S. strategists and planners. With the United States 

attempting to extend deterrence across land, sea, air, space, and cyber space, 

for example, what is the threshold of adversary action the U.S. military 

should seek to deter? How will the United States distribute scarce resources 

across its critically important strategic domains?

The Obama administration is attempting to increase its defense 

engagement with U.S. allies and partners to better tailor its extended 

deterrence and assurance strategies to specific regional challenges, to 

include substantive discussions with foreign governments on U.S. nuclear 

strategies, forces, and posture. While broadly appreciated by many allies, 

this direct engagement on issues raises the possibility that in the future the 

United States may have to turn down direct allied requests regarding the 

U.S. “nuclear umbrella” or other defense arrangements, potentially reducing 

the influence of Washington over allied national security decision-making 

processes. In addition, U.S. allies generally support Washington’s efforts to 

negotiate verifiable reductions of nuclear forces, but are increasingly 

concerned about the possible effect these reductions will have on the ability 

of the United States to protect them from nuclear threats. 

U.S. nuclear-capable aircraft – long-range bombers such as the B-52

and fighter-bombers such as the F-16 – currently represent the linchpin of 

U.S. assurance strategies and are also critical to extended deterrence 

strategies. These visible, flexible nuclear forces assure allies and deter their 

adversaries, providing a clear demonstration of the U.S. nuclear umbrella 

through their presence in theater either through permanent basing, regular 

rotations, or strategic forward deployment in times of crisis. However, this 

reliance on nuclear-capable aircraft raises questions regarding the current 

and future placement and rotation of these assets. U.S. allies also hold 

mixed views regarding the relative decline of the role of nuclear forces 

within U.S. plans and policies for their defense.

Tailored Regional Considerations

The distinctive assurance requirements of each ally, and the 

differing deterrence challenges posed by each of their potential adversaries, 

require the United States to individually tailor its assurance and extended 

deterrence strategies. 

Each region poses its own unique challenges to the development of 

these strategies. The United States’ stated intent to “rebalance” to the 

strategically vital and dynamic region of East Asia, for example, has raised 
xv

questions abroad regarding both the future U.S. defense posture across the 

Asia-Pacific and its current extended deterrence/assurance strategy of 

maintaining a “continuous presence” of nuclear-capable bombers in theater. 

This has led some U.S. allies in East Asia to express a desire for more 

visible extended deterrence capabilities. 

In the Middle East, Iran’s pursuit of an independent nuclear weapon 

capability has led regional allies and partners to seek closer defense 

cooperation with the United States, albeit outside of a formal alliance 

structure. If Iran becomes a nuclear power, regional rivalries and political 

sensitivities will complicate efforts to develop a “nuclear umbrella” concept 

for the region. While missile defenses are playing an increasingly important 

role in regional extended deterrence and assurance strategies, Iran’s large 

number of ballistic missiles will continue to pose a threat to U.S. regional 

allies and forward deployed forces for the foreseeable future. How the 

United States counters this and other regional threats in light of an increased 

focus on East Asia and other potential global demands upon missile defenses 

presents a complex challenge for U.S. defense planning. 

Finally, in Europe the traditional security commitments to NATO 

members remain in place. The 2012 NATO Deterrence and Defense Posture 

Review (DDPR) confirmed that NATO remains a nuclear alliance. The 

DDPR did not address, however, looming challenges to the alliance’s 

current nuclear strategy and nuclear sharing arrangements. Most allied dualcapable aircraft are slated for retirement within the next decade, and there 

are no plans in place for their replacement. NATO’s current embrace of 

missile defenses has provided an avenue for close cooperation on one aspect 

of extended deterrence/assurance strategies, but also represents an irritant to 

Russia. Ongoing European military force reductions and general uncertainty 

about NATO’s future strategic direction raise broader questions about the 

future of extending deterrence in this region when the alliance has no clear 

enemy. 

U.S. extended deterrence and assurance guarantees remain vital to 

U.S. and allied national security, and play a critical role in ensuring stability 

in strategically vital regions across the globe. They face pressure, however, 

not only from geopolitical developments but also from changing

requirements reflecting evolving adversary capabilities and shifting allied 

requests. Washington’s present role as chief national security partner of 

critical allies, its influence in key regions, and, ultimately, U.S. security and 

prosperity within an increasingly globalized and interconnected world, will 

all depend on how successfully the United States tailors policies and 

strategies to assure its friends – and deter their enemies – in a dynamic 

international security environment.
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1

EXTENDED DETERRENCE AND ALLIED ASSURANCE

PART 1: INTRODUCTION

The United States’ global network of defense alliances and 

security partnerships is critical to U.S. national security, regional 

stability, and international order. In the complex 21st century 

geopolitical environment, U.S. allies and partners face potential threats 

from a range of state and non-state actors. In addition to protecting the 

American homeland through deterrence of adversary threat or attack 

(called central deterrence), the United States has also made solemn 

commitments to defend certain key allies and friends around the world 

from enemy coercion or assault (called extended deterrence). In other 

words, in order to protect itself, its allies, and its vital geostrategic 

interests, the United States must simultaneously:

 Protect the U.S. homeland, national interests, and freedom of 

action through central deterrence of adversaries;

 Protect its allies and partners from intimidation, coercion, or 

attack by deterring their potential adversaries, a strategic concept 

known as extended deterrence; and

 Assure its allies and partners that the United States is fully 

committed to defending them against a host of potential threats, 

a strategic concept known as assurance.

The successful exercise of extended deterrence and allied 

assurance requires the combined efforts of national leaders, policy 

makers, diplomats, defense strategists, and military planners. The 

effective tailoring of extended deterrence and assurance strategies 

requires constant communication with allies and constant intelligence on 

adversaries conducted by diplomatic posts, intelligence services, defense 

officials, and relevant commands operating in concert across the 

diplomatic, information, military, and economic domains. In order to 

successfully apply all the instruments of national power to the realization 

of U.S. extended deterrence and assurance commitments, all of these 

actors must leverage their unique expertise on national security matters 

and share information on the views, goals, and capabilities of the 

country’s allies and adversaries. These actors must also work closely 

with each other in order to effectively synchronize U.S. policies, 

strategies, actions, and operations designed to communicate the 

credibility of U.S. security guarantees to foreign audiences (both friendly 

and hostile). This credibility is not solely a function of military plans or 

actions. It is dependent on convincing both adversaries and allies that 
2

the United States possesses the political resolve to maintain its allied 

defense commitments in times of crises and has the military capability to 

fulfill these promises in times of conflict. 

This paper provides a baseline framework – in the form of 

definitions, concepts, current guidance, and historical background – that 

can assist civilian defense officials and military officers tasked with 

developing strategies, plans, and operations for extended deterrence and 

assurance. Its research and analysis is focused on defense and military 

strategy issues; the strategic concepts of extended deterrence and 

assurance issues are not solely defined by national security 

considerations, but they are centered on the potential use of armed force 

to protect U.S. allies and, if necessary, punish their enemies. A broad 

range of government and non-government sources informs this paper’s 

research, assessments, and conclusions. The authors interviewed a 

number of U.S. government (USG) subject matter experts and also 

analyzed official policy documents, Department of Defense (DoD) 

guidance, joint U.S.-foreign government statements, and other sources of 

information guiding the development of extended deterrence/assurance 

strategies, plans and operations. Non-government sources included 

academic literature and recent reports by research institutions on the 

topics of extended deterrence and assurance. 

The paper is divided into five parts: 

 Part 2 defines extended deterrence and allied assurance and 

proposes a model for illustrating these strategic concepts; 

 Part 3 provides a historical overview of the evolution of U.S. 

deterrence, extended deterrence and assurance concepts from the 

Cold War to the present day; 

 Part 4 examines continuity and change in U.S. extended 

deterrence and assurance policies, strategies, and forces during 

the Cold War and post-Cold War era through 2008;

 Part 5 summarizes current administration guidance documents 

and policy statements on deterrence, extended deterrence, and 

allied assurance, and identifies a number of issues and challenges 

facing U.S. extended deterrence and assurance policies 

strategies;

 Part 6 discusses U.S. extended deterrence and assurance 

commitments and directives by geographic region, to include 

assessments of the unique challenges each region presents to 

developing and implementing strategies for defending local 

allies and deterring their potential adversaries. 
3

PART 2: DEFINITIONS AND FRAMEWORK

Definitions

As noted by National Defense University scholar Elaine Bunn, 

“[o]f course, in order to extend deterrence, the United States must first be 

able to deter.”1 Extended deterrence and assurance cannot be defined or 

understood separate from the concept of central deterrence. The three 

represent closely related, but nonetheless distinct, strategic concepts. 

Careful definition and use of each is important, as public statements, 

national security analyses, and academic publications sometimes confuse 

or conflate the terms. This section provides operating definitions of 

deterrence, central deterrence, extended deterrence, and assurance as 

strategic concepts (defined here as concepts that inform the development 

of national security policy, defense strategies, and military operations); 

discusses the relationships between the four; and identifies two key 

challenges embedded within these concepts. 

Deterrence

Joint Publication 1-02, Department of Defense Dictionary of 

Military and Associated Terms defines “deterrence” as “the prevention 

from action by fear of the consequences. Deterrence is a state of mind 

brought about by the existence of a credible threat of unacceptable

counteraction.”2 The 2006 Department of Defense (DoD) document 

Deterrence Operations Joint Operating Concept provides further detail 

by placing the concept of deterrence within an operational context: 

[deterrence operations] convince adversaries not to take 

actions that threaten US vital interests by means of 

decisive influence over their decision-making. Decisive 

influence is achieved by credibly threatening to deny 

benefits and/or impose costs, while encouraging restraint 

by convincing the actor that restraint will result in an 

acceptable outcome.3

Practitioners, analysts, and scholars also differentiate between 

two main categories or types of deterrence: 

1) Deterrence by punishment: A geopolitical actor elects not to 

undertake a particular action due to its fear the action will trigger 

a response from a second party capable of imposing 

unacceptable costs against it; 

2) Deterrence by denial: A geopolitical actor elects not to 

undertake an action due to its belief a second party has taken, or 
4

will take, steps to ensure this action will fail to achieve its 

desired result.

Both types of deterrence are included within current U.S. 

government policy. The 2012 DoD guidance document “Sustaining U.S. 

Global Leadership” states: 

Credible deterrence results from both the capabilities to 

deny an aggressor the prospect of achieving his 

objectives and from the complementary capability to 

impose unacceptable costs on the aggressor.4

These definitions provide a baseline understanding of deterrence 

as a theoretical construct and an operational concept. When discussing 

deterrence in terms of strategies and operations, it is important to 

supplement the definitions above with the following understandings: 

1) Deterrence is in the eye of the beholder; it is rooted within the 

internal beliefs, fears, and other internal/psychological processes 

of the actor the United States is attempting to deter; 

2) Deterrence is a dyadic or two-party construct involving the 

United States and the party it seeks to deter; 

3) Deterrence includes the strategic use of all tools of state power, 

to include the use of diplomatic actions, economic sanctions, and 

military force;

4) In terms of military forces, both offensive and defensive 

capabilities play a role in deterring potential adversaries; 

deterrence is not limited to nuclear forces and the massive 

destructive power they can visit upon a potential adversary;5and

5) Deterrence is an overarching concept that is applicable to a broad 

spectrum or series of actions the United States wishes to deter. 

Central deterrence and extended deterrence are distinct 

subcategories within this broader concept, as explained below.

Central Deterrence

Central deterrence (sometimes called general, core or national 

deterrence) refers to U.S. policies, strategies, and operations that threaten 

costs, deny benefits, or encourage restraint in regard to an adversary 

taking an action against the United States (defined as the United States 

government, U.S. citizens, or U.S. territory). Within the Cold War 

context of the nuclear rivalry between the United States and Soviet 

Union, for example, central deterrence was often understood as “attempts 
5

to discourage attacks upon the deterrer’s homeland, e.g., dissuading 

Soviet nuclear attacks against the United States.”6

Using generic terms, a basic description of central deterrence is 

Blue deterring potential adversary Red from taking actions to undermine, 

intimidate, coerce, or attack Blue. 

Extended Deterrence

As a country with global interests, the United States has long 

recognized that international peace and stability is essential to U.S. 

national security. Unrest, conflict, and disorder overseas give rise to 

transnational threats that threaten all international actors, including the 

United States. In this geopolitical environment, the safety and prosperity 

of the United States is closely intertwined with the security of its allies 

and partners abroad. As a result, the United States has a vested interest 

in deterring threats or attacks against countries far from its own borders. 

The United States thus seeks to extend deterrence beyond simply 

deterring attacks against the U.S. homeland. As a strategic concept, 

extended deterrence involves the United States using all the tools of state 

power, to include the use of military force, to deter a foreign actor from 

undertaking hostile actions against a third party. This third party is often 

an ally or partner; however, in the protection of vital regions or interests, 

the United States may also extend deterrence to prevent harm against 

neutral or even adversarial states.7 This extension of geopolitical capital 

and national resources to cover or protect a third party from attack has 

often led to the use of “umbrella” or “shield” analogies to describe the 

phenomena of extended deterrence. 

Using generic terms, extended deterrence can be described as 

Blue deterring adversary Red from taking actions to intimidate, coerce, 

or attack third-party Green. While the desired outcome of extended 

deterrence is the preservation and protection of Green, the focus and 

object of extended deterrence as a strategic concept is Red. Green may 

be passive, indifferent, or even unaware of the actions of Blue. For Blue, 

extended deterrence is centered on the following question: What deters 

Red from coercing, threatening, or attacking Green? In today’s 

multipolar environment, the question is often a complex one for the 

United States to answer, as there are several possible “Reds” and many 

“Greens,” and each Blue-Red and Blue-Green interaction can have 

second-order effects on other states. 

Assurance 

In extending deterrence beyond its own borders, the United 

States seeks to convince foreign parties that if an aggressor chooses to 
6

attack a third party under U.S. protection, it will suffer costs and/or fail 

to achieve its goals. As noted above, the focus of extended deterrence is 

on the potential adversary and not the third party the United States is 

attempting to protect from coercion or attack. 

If the third party does not know or believe that the United States 

will take action to deter threats against it, however, it may act in a 

manner that complicates or abrogates U.S. efforts to extend deterrence 

against its potential adversary. As a result, extending deterrence against 

states of concern is not sufficient for ensuring regional order or 

international peace and stability. 

This underlines the critical importance of close engagement with 

U.S. allies and partners in developing the policies, strategies, and 

operations that will protect them from potential adversaries. The United 

States must convince its allies and partners they are protected by credible 

U.S. security guarantees. This requires consistent, constant, and visible 

demonstrations of U.S. political resolve and military capabilities to 

reinforce the communication of assurance messages. 

The assurance of allies or partners thus represents a strategic 

concept closely related to, but nonetheless separate from, extended 

deterrence. As a strategic concept, assurance represents the means and 

methods employed to convince a U.S. ally or partner that the United 

States can guarantee its safety from intimidation, coercion, or attack by 

foreign actors. In many cases, this includes a pledge by the United States 

to use military force to protect the ally or partner from potential 

adversaries. It can also include the visible conduct of exercises and 

operations to demonstrate resolve, either conducted unilaterally by the 

United States or in concert with the ally or partner.

Using generic terms, allied assurance is Blue undertaking actions 

to assure Green it will deter Red from threatening or harming Green. 

The goal is the same as extended deterrence: preventing Red from 

intimidating, coercing, or attacking Green. For assurance, however, the 

focus of Blue’s attention is on Green, and taking steps to demonstrate 

that it is protected from Red. It may also require Blue to shape Green’s 

actions in order to prevent complicating the dyadic deterrence 

relationship between Blue and Red. For the purposes of assurance, Blue 

must balance the development of deterrence strategies for Red with the 

needs and requests of Green. Importantly, as discussed in further detail 

below, the requirements of assurance may differ from the requirements 

of extended deterrence. Discussions with allies, for example, may reveal 

that their views of what deters a potential adversary differ from those of 

the United States. If the United States concludes it must realign its 

position to more closely match the views of a particular ally, it may find 
7

it necessary to employ two separate (if not necessarily distinct) strategies 

– and two sets of associated plans, operations, and forces – for 

preventing Red from attacking Green, with one set tailored to deter Red 

from attacking Green, and a second tailored to assure a specific Green it 

is protected from Red.8 Strategists and planners must recognize that the 

demands of extended deterrence and assurance may prove “additive and 

cumulative, despite some fungibility between them.”9

Conceptual Framework for Extended Deterrence and Assurance

The effectiveness of extended deterrence and assurance relies 

upon the successful integration of a range of diplomatic, informational, 

military, and economic elements into strategies, plans, and operations. 

Together these elements must demonstrate the credibility of U.S. defense 

guarantees to both adversaries and allies by doing the following: 

 Demonstrating Political Resolve: Foreign actors must believe 

that U.S. security pledges to allies and partners are fully 

supported by U.S. political and military leaders, are fully 

complementary to broader U.S. geopolitical objectives, and are 

sealed by a politically or legally binding commitment the United 

States will, in fact, fulfill. In addition, allies and their possible 

adversaries must believe the United States is prepared to bear the 

potential costs an adversary can impose against it when the U.S. 

government and military forces respond in defense of an ally (to 

include attacks on U.S. troops deployed abroad or even 

retaliatory strikes against the U.S. homeland).

 Applying Effective, Tailored Military Capabilities: Foreign 

actors must also believe the United States will match its political 

commitment with a robust, diverse mix of forces capable of 

projecting power and deterring aggression across all relevant 

strategic operating environments. In addition, the United States 

must convince foreign actors it is capable of developing and 

implementing strategies, plans, and operations for protecting 

allies that are tailored to directly address the unique threats and

challenges they face.10

Figure 2.1 presents a model of extended deterrence and 

assurance as political-military strategic concepts. It is illustrative rather 

than exhaustive; not all potential components of extended deterrence and 

assurance are included within the model. In its depiction of extended 

deterrence and assurance as frameworks constructed on twin pillars of 

political resolve and military capability, however, it reflects a consensus 
8

between national security practitioners and scholars regarding the 

fundamental political-military character of both concepts.i 

The political and military components of this model represent a 

range of potential means and methods for developing extended 

deterrence and assurance strategies. A combination of both is critical to 

deterring adversaries and assuring allies. However, the specific mix of 

these components, or balance between them, will differ based on the 

specific requirements necessary to assure a particular ally or deter a 

potential adversary. Importantly, this drives a requirement for the United 

States to consider developing individually tailored assurance strategies 

 

i

Figure 1.1 represents a model developed from an earlier extended deterrence 

model constructed by Darci Bloyer and Zechariah Becker of SAIC. It also 

combines elements of a model presented within the Center for Strategic and 

International Studies 2008 report titled Exploring the Nuclear Posture 

Implications of Extended Deterrence and Assurance and is further informed by 

discussions with key subject matter experts. Darci Bloyer and Zechariah Becker, 

“Building a U.S. Extended Nuclear Deterrent for the 21st Century,” briefing, 

CSIS Project on Nuclear Issues, October 9-10, 2008, and Clark Murdock et al. 

Exploring the Nuclear Posture Implications of Extended Deterrence and 

Assurance (Center for Strategic and International Studies: Washington D.C., 

November 2009).
9

for each ally or partner and to also develop individually tailored extended 

deterrence strategies for these actors’ potential adversaries.

The political and military means and methods included within 

this conceptual model, and their role within extended deterrence and 

assurance, are discussed in further detail below. The next three sections 

– “Political Resolve,” “Political-Military Support,” and “Military 

Capability” – also provide historical and contemporary examples to 

illustrate how the United States uses these various political, politicalmilitary, and military elements to provide assurance in response to 

specific allied and partners’ concerns and/or to deter specific threats from 

the latter’s potential adversaries.

Political Resolve

The political dimension of extended deterrence and assurance 

includes a range of geopolitical and national policy means, methods, and 

messages. These components are vital to establishing the United States 

as a credible, reliable ally that is strategically invested in the defense of 

foreign states. Through statements and actions, it is critically important 

the United States communicate and demonstrate it possesses the political 

resolve to fulfill its security guarantees, even if they may entail 

significant costs – up to and including the risk of retaliation against the 

U.S. homeland. This section will discuss four elements of political 

resolve: (1) public statements and personal diplomacy by national 

leadership; (2) national strategic guidance; (3) national policies on use of 

force, and; (4) defense treaties and security agreements. 

Public Statements and Personal Diplomacy by National 

Leadership. Due to its status as a global superpower, the speeches, press 

briefings, and other public statements of U.S. leaders are closely 

monitored by U.S. allies, partners, and potential adversaries. This close 

reading by foreign parties of statements by the U.S. president and highranking U.S. government officials occurs regardless of whether they are 

delivered before a domestic or foreign audience.11

Strong statements from U.S. leaders pledging support to the 

defense of friends abroad plays a critical role in assuring allies.12

Recognizing this fact, U.S. presidents from the Cold War to the present

day have often included expressions of support for allies and partners –

along with warnings for potential adversaries – within major speeches, 

such as the annual State of the Union address delivered to Congress.13

Stating – and restating – security guarantees to allies and 

partners is also a necessary component of initial responses to regional 

security crises and U.S. diplomatic visits to foreign states. It is difficult 
10

to overemphasize the degree to which U.S. senior leadership statements 

are pored over by government officials and members of the media in 

foreign capitals. Foreign governments, and their publics, require clear, 

direct confirmation from the United States that its leaders are personally 

and politically invested in protecting them from coercion and 

aggression.14 Moreover, in cases where political or other circumstances 

prevent the United States and a partner from concluding formal defense 

arrangements, assurance relies heavily on the word of the president (or 

his/her designated representative), which in lieu of a written treaty or 

agreement, may serve as the basis for the two states’ security 

relationship.

National leadership statements affirming the defense of allies 

and partners are also important for extended deterrence. They 

communicate a strong signal to potential adversaries that certain 

countries are under the protection of the United States. When delivered 

by the president, they are understood to represent promises backed by the 

commander-in-chief of the world’s sole superpower. As a result, the text 

of speeches articulating “red lines” that, if crossed, will provoke a 

military response by the United States, can effectively deter foreign 

actors from threatening or attacking U.S. allies and partners abroad. 

For strategists and planners, the statements of U.S. leaders and 

key officials may occasionally signal a shift in extended deterrence and 

assurance priorities, but will usually underscore existing strategic 

guidance (see “Statements on National Strategy” section below). In 

either case, addresses and other official public remarks represent 

extended deterrence and assurance guidance and messaging at the 

highest level. Policies and plans to implement the geopolitical vision of 

national leadership must align with the key themes and overall narrative 

presented within these public statements.

Example of Public Diplomacy. In March 2010, the Republic of 

Korea (ROK) corvette Cheonan suffered a sudden explosion and sank in 

the Yellow Sea with the loss of 46 South Korean sailors. Two months 

later, following an investigation of the incident by a team of international 

experts, the ROK government publicly accused the Democratic People’s 

Republic of Korea (DPRK) of launching an unprovoked attack against 

the vessel.

15

 The White House immediately issued a statement backing 

its ally and pledged to defend it against any further DPRK attempts to 

coerce or attack the ROK:

U.S. support for South Korea’s defense is unequivocal, 

and the President has directed his military commanders 

to coordinate closely with their Republic of Korea 
11

counterparts to ensure readiness and to deter future 

aggression .... The U.S. will continue to work with the 

Republic of Korea and other allies and partners to reduce 

the threat that North Korea poses to regional stability.16

President Obama followed up on this and other U.S. government 

statements of support for the ROK during a visit to South Korea the 

following November. At a joint press conference with ROK President 

Lee Myung-bak held at the Blue House (the ROK equivalent of the 

White House), he criticized the DPRK for the Cheonan sinking and its 

ongoing pattern of “belligerent behavior.” Within his remarks, President 

Obama also emphasized the enduring strength of U.S. security 

guarantees to ROK, stating “we can never say it enough – the United 

States will never waver in our commitment to the security of the 

Republic of Korea.”17 In terms of timing, delivery, and content, the 

White House crafted the public statements in May and November 2010 

to simultaneously assure the ROK of U.S. support throughout the 

Cheonan crisis and deter the DPRK from launching any further attacks. 

National Strategic Guidance. As a country with an open 

political process, U.S. strategic guidance is often readily available for 

reading by any interested party, whether U.S. or foreign. Most U.S. 

presidential administrations in the modern era openly publish and 

distribute a National Security Strategy (NSS), Quadrennial Defense 

Review (QDR), and other key defense guidance documents (such as the 

Obama administration’s decision to publish the 2010 Nuclear Posture 

Review Report (NPR)). These public documents articulate their 

perspective on current world affairs, identifying strategic priorities and 

stating the strategies and policies they intend to implement in pursuit of 

these goals. Together, these documents orient the U.S. government 

within the contemporary geopolitical environment and communicate key 

strategic objectives to individual departments and agencies, to include 

the Department of Defense and U.S. armed forces. 

Similar to the public pronouncements of U.S. leaders and 

officials, the national strategic guidance documents of the U.S. 

government are closely (and often painstakingly) scrutinized by foreign 

audiences.18 America’s friends abroad, and their potential enemies, read 

these documents for any U.S. statements or signals (whether direct or 

implied) concerning Washington’s views on international security threats 

and the costs it is willing to bear in order to defend allies and partners 

overseas.19 For the purposes of extended deterrence and assurance, it is 

important for adversaries reading these documents to understand that 

U.S. geopolitical strategy closely links the national security of the United 
12

States with the safety and security of its allies and partners abroad. 

Potential adversaries reviewing examples of U.S. national strategic 

guidance should also readily and unambiguously conclude the United 

States is strongly committed to devoting significant resources to planning 

and preparing to defend its friends overseas against a range of threats. 

For strategists and planners, national statements of strategic 

intent provide direct guidance establishing the key objectives of extended 

deterrence and assurance strategies, expressly identifying regions and 

states that require the protection of the United States. Presidential and 

Department of Defense strategic guidance documents also present U.S. 

leadership perspectives on deterrence concepts (sometimes to include 

specific discussion of force requirements) that direct the development of 

specific extended deterrence and assurance strategies and operations. As 

discussed in further detail below, U.S. views on extended deterrence and 

assurance have evolved since the end of the Cold War, with the guidance 

documents of each post-Cold War administration contributing to this 

process. This underscores the critical importance of strategists and 

planners closely studying both past and present guidance to understand 

how the U.S. government practice of extended deterrence and assurance 

has changed over time and the corresponding impact of these changes on 

military plans, operations, and capabilities. 

Examples of National Strategic Guidance. Written during a 

period of warming relations between the two Cold War superpowers, but 

prior to the collapse of the Soviet Union, President George H.W. Bush’s 

1990 National Security Strategy articulated a global strategy balancing 

increased diplomatic engagement with Moscow with the continued 

sustainment of robust deterrent capabilities: 

The U.S. will seek to engage the USSR in a relationship 

that is increasingly cooperative ... [however, the] United 

States must continue to maintain modern defenses that 

strengthen deterrence and enhance security. We cannot 

ignore continuing Soviet efforts to modernize 

qualitatively even as they cut back quantitatively.20 

The guidance document also included direct reassurances to U.S. 

allies uncertain of the regional implications of a potential thaw in the 

Cold War rivalry between the United States and Soviet Union. A section 

on Asia within the document, for example, highlighted the enduring 

importance of relationships with longtime allies such as Japan: “[o]ur 

alliance with Japan remains a centerpiece of our [regional] security 

policy and an important anchor of stability.”21
13

Current guidance documents, such as the 2010 NSS and the 2012 

DoD publication “Sustaining U.S. Global Leadership,” (2012 DSG) 

present a global strategic vision stressing America’s vital role in 

promoting international stability, to include the identification of a 

number of specific extended deterrence and assurance objectives. The 

two documents include strong statements emphasizing the United States’ 

continuing commitment to the security of traditional allies, describing 

NATO as the world’s “pre-eminent security alliance” and pledging to 

work with European allies to “strengthen our collective ability to 

promote security, deter vital threats, and defend our people.”22 The 

documents also stress the critical importance of U.S. military forces –

particularly those located in theater – to deterring “destabilizing” states 

such as Iran, stating “the United States will continue to place a premium 

on U.S. and allied military presence in –and support of – partner nations 

in and around this region.”

23

 Citing the growing strategic importance of 

the Asia-Pacific region, the 2012 Defense Strategic Guidance (DSG) also 

directs the DoD to “rebalance” toward this theater, shifting resources 

toward security challenges such as maintaining open sea-lanes in the 

Western Pacific and protecting East Asian allies and partners.24

Current guidance documents thus provide express guidance 

regarding capabilities and regional objectives for U.S. extended 

deterrence and assurance strategies. They also communicate messages to 

foreign audiences regarding the vital strategic importance the United 

States assigns to protecting key allies (e.g., Japan, Korea, and other allies 

and partners in the Asia-Pacific), deterring specific actors (such as Iran 

and the DPRK), and deterring actions that could jeopardize regional 

stability and international peace (such as efforts to restrict freedom of 

navigation). 

Policies on the Use of Force (Declaratory Policy). Policies 

regarding when, where, and how to use force are an important 

component of extended deterrence and assurance strategies, identifying 

potential “trip wires” regarding when adversary actions against allies will 

prompt a U.S. military response and shaping foreign perceptions of the 

potential costs this response will impose upon the targeted actor. This 

section focuses on declaratory policy, which refers to unclassified U.S. 

policy documents and public statements on the potential use of nuclear 

weapons, to include U.S. government statements on the circumstances or 

adversary actions that could lead the president to contemplate ordering a 

nuclear strike. 

With many U.S. allies and partners facing potential adversaries 

armed with nuclear arsenals or committed to the development of nuclear 
14

weapons, U.S. declaratory policy plays a key role in extended deterrence 

and assurance. Allies and partners concerned about nuclear threats are

particularly interested in U.S. policies regarding a response to nuclear 

provocations or attacks aimed against them rather than at the United 

States; they require a clear commitment within U.S. declaratory policy 

that Washington will extend a U.S. “nuclear umbrella” over their states, 

protecting them from the nuclear forces of their potential adversaries.

For the purposes of extending deterrence, U.S. declaratory policy 

also communicates to nuclear-armed adversaries that a central role of the 

U.S. nuclear arsenal is deterring nuclear attacks against U.S. allies and 

partners and that any such attack on a U.S. friend abroad will trigger a 

devastating response by the United States.25 Beyond this clear linkage 

between a nuclear response to a nuclear attack on an ally or partner, 

however, the United States has generally practiced a degree of ambiguity 

in regard to its declaratory policy in terms of possible use of nuclear 

forces should it conclude extended deterrence was failing or at risk of 

failure. This often reflected an interest in deliberately sowing 

uncertainty in the minds of potential adversaries of allies and partners; 

during the Cold War, for example, the United States rejected Soviet 

efforts to propose a mutual declaration of “no first use” of nuclear

weapons in part to leave Moscow and its Warsaw Pact allies uncertain as 

to what level of escalation or incursion in Western Europe might prompt 

a U.S. nuclear response.26

For allies and partners that face adversaries building or wielding 

nuclear arms, U.S. declaratory policy may represent the linchpin of their 

security relationship with the United States. Some U.S. allies and 

partners have had longstanding concerns with regard to the willingness 

of the United States to use nuclear weapons on their behalf and to expose 

themselves to possible nuclear retaliation as a result of this 

intervention.27 Their assurance in the face of an existential nuclear threat 

requires the United States to publicly declare it is prepared to use nuclear 

force to deter a nuclear attack on an ally and, if necessary, will respond 

to a nuclear attack even if this risks an adversary response against the 

American homeland.28 

For strategists and planners, declaratory policy provides critical 

context and overarching guidance for nuclear forces at the public, 

unclassified level. The implementation of this guidance, however, is 

necessarily discussed and directed at a highly classified level. Strategists 

and planners must recognize that much or all of these latter discussions 

will remain unknown to foreign parties. As a result, the development 

and implementation of nuclear strategies, plans, and operations should be 
15

sensitive to (potentially premature or inaccurate) conclusions drawn by 

allies and partners from their reading of U.S. declaratory policy.

 

Examples of Declaratory Policy. U.S. declaratory policy has 

evolved over time; during the early Cold War, for example, the United 

States issued a number of statements communicating its readiness to use 

nuclear weapons to prevent the numerically superior conventional forces 

of the Warsaw Pact from overwhelming NATO.29 Declaratory policy 

has changed to reflect the declining threat of major nuclear attack in the 

post-Cold War era while also recognizing the enduring challenges posed 

to the United States and its allies by a number of potential adversaries 

possessing nuclear and other WMD. Current U.S. declaratory policy is 

stated in the 2010 NPR. The key guidance statements within the 

document are summarized below: 

 The United States will only contemplate nuclear weapon use in 

“extreme circumstances.” “The United States would only 

consider the use of nuclear weapons in extreme circumstances to 

defend the vital interests of the United States or its allies and 

partners.”30

 The United States is not prepared to adopt a “sole purpose” 

policy for nuclear weapons. Due to the fact that a number of 

states with nuclear weapons programs remain outside the NPT 

regime, the United States is “not prepared at the present time to 

adopt a universal policy that deterring nuclear attack is the sole 

purpose of nuclear weapons, but will work to establish 

conditions under which such a policy could be safely adopted.”31

o The United States will continue to consider a possible 

nuclear response in “extreme circumstances to defend 

the vital interests of the United States or its allies or 

partners” to include chemical, biological, and/or 

conventional attacks by states with nuclear weapons 

and/or outside of the NPT regime. For “states that 

possess nuclear weapons and states not in compliance 

with their nuclear non-proliferation obligations – there 

remains a narrow range of contingencies in which U.S. 

nuclear weapons may still play a role in deterring a 

conventional or CBW [chemical or biological warfare] 

attack against the United States or its allies and 

partners.”32 

 The United States will provide “negative security assurance” to 

states in good standing with the Nuclear Non-proliferation 
16

Treaty (NPT). “The United States will not use or threaten to use 

nuclear weapons against non-nuclear weapons states that are 

party to the NPT and in compliance with their nuclear nonproliferation obligations;”33

o In addition, the United States will not respond with 

nuclear weapons to chemical or biological weapon 

attacks by non-nuclear and NPT states: For states 

without nuclear weapons or nuclear weapon programs 

outside of the NPT regime, the United States, at the 

present time, will use overwhelming conventional force 

– but not nuclear weapons – in response to a chemical or 

biological weapons attack. The 2010 NPR also states, 

however, that the United States reserves the right to 

amend the preceding policy if the lethality and general 

risk posed by biological weapons increases in the 

future.34

Current declaratory policy seeks to reduce the salience of nuclear 

weapons for foreign states by reducing their role within U.S. defense 

planning and emphasizing the security benefits of adhering to the NPT 

and other nonproliferation standards. The 2010 NPR also emphasizes, 

however, that the U.S. “nuclear umbrella” will continue to deter nuclear 

and – in certain circumstances – CBW and conventional attacks against 

U.S. allies and partners.

Defense Treaties and Security Agreements. In some regions, 

United States assurances to security partners are primarily based upon 

interactions centered on the personal relationships between U.S. and 

foreign leaders, with unwritten guarantees offered verbally during 

councils held behind closed doors. The majority of U.S. defense 

commitments to allies and partners, however, are codified within official 

texts laying out the terms of the security partnership. These can take the 

form of either politically binding agreements or legally binding treaties.

The United States attaches a high degree of importance to 

meeting its defense treaty and security agreement commitments to U.S. 

allies and partners abroad. In order to fulfill these obligations, it has 

military forces stationed across the globe and has repeatedly 

demonstrated its willingness to rapidly respond with overseas 

deployments – and, when necessary, offensive and defensive operations 

– to defend its allies and partners. 

The close ties represented by a legally binding security pact 

highlight the importance attached by the United States and foreign 
17

parties – both allied and adversary – to written extended deterrence and 

assurance commitments. For potential adversaries of U.S. allies and 

partners, the existence of formal security arrangements between the 

United States and these governments considerably raises the costs of any 

effort to coerce, intimidate, or attack these actors. They must account for 

the likelihood the United States will meet its defense commitments and 

militarily intervene on behalf of its allies and partners. 

Similarly, many U.S. allies and partners view these texts as the 

foundational, contractual documents sealing their friendship with the 

United States and ensuring the latter’s enduring commitment to protect 

them against foreign adversaries. Many U.S. allies view defense treaties 

and agreements with the United States as central to their national 

security. The ROK Embassy in the United States, for example, describes 

the ROK-U.S. Mutual Defense Treaty negotiated in 1953 as “the bedrock 

supporting the growth of democracy and prosperity in Korea.”

35

For strategists and planners, treaties and agreements establish 

firm U.S. commitments to the defense of certain allies and partners and 

may also shape when, where, and how this commitment is realized. In 

some cases, these commitments may include provisions discussing or 

identifying certain strategies, plans, operations and forces associated with 

this response. Strategists and planners must be aware of the expectations 

of U.S. policymakers – and friends abroad – in regard to the expected 

timing, placement, and provision of U.S. military force associated with 

treaty and agreement guarantees.

Example of Defense Treaty. Perhaps the best-known example of 

a U.S. treaty commitment to the defense of allies is Article V of the 1949 

Washington Treaty (also known as the North Atlantic Treaty), which 

established the North Atlantic Treaty Organization (NATO). Article V 

commits all members of the alliance to mount a common response 

against any attack directed against an individual NATO state:

The Parties agree that an armed attack against one or 

more of them in Europe or North America shall be 

considered an attack against them all and consequently 

they agree that, if such an armed attack occurs, each of 

them ... will assist the Party or Parties so attacked by 

taking forthwith, individually and in concert with the 

other Parties, such action as it deems necessary, 

including the use of armed force, to restore and maintain 

the security of the North Atlantic area.36

During the Cold War, the U.S. commitment to upholding Article 

V assured members of NATO that the United States would defend 
18

Western Europe if it came under attack by the Soviet Union and its allies. 

This belief was critical to the integrity of an alliance whose strongest 

member was the United States. The central involvement of the United 

States in an alliance where an armed attack upon any member would 

prompt an immediate military response from Washington also deterred 

the Soviet Bloc from using military force to interfere with, coerce, or 

overwhelm NATO’s European members. 

Political-Military Support

A number of key elements of extended deterrence and assurance 

represent the intersection of 

 U.S. political decisions to protect allies and partners against 

foreign threats;

 Military forces assigned to foreign regions or states in order to 

achieve these missions and objectives; and

 Direct engagement of foreign states to support the above 

processes. 

The political-military elements discussed here bring together the 

political credibility of the United States as a committed ally, the military 

capabilities of a superpower capable of dispatching forces and defeating 

potential opponents across the globe, and the direct support of a U.S. ally 

or partner providing critical national resources (such as territory and/or 

military forces) to support U.S. extended deterrence and assurance 

strategies. Open political decisions visibly designating U.S. forces to the 

defense of specific allies and partners are extremely valuable for the 

purposes of assuring allies and deterring their potential adversaries. In 

general, the greater the permanence of the assignment of U.S. military 

personnel abroad, the greater the assurance value, with permanently 

based forces – in some cases, to include non-strategic nuclear forces –

often representing the highest form of assurance the United States can 

provide to its allies and partners. 

This section discusses two elements of political-military support 

to extended deterrence and assurance: (1) visible engagement, to include 

both direct consultations with U.S. defense officials and joint exercises 

with U.S. military forces, and; (2) basing arrangements and regular 

rotations whereby allies welcome U.S. forces and host them on their 

home territory, either stationed at permanent bases or as part of a regular 

troop rotation for joint defense and training purposes. 

Visible Engagement (Consultative Mechanisms). While 

alliances and partnerships are frequently forged through the drafting of 
19

written agreements, the maintenance of these relationships is often 

realized through the diplomatic engagement that follows. In order to 

implement security agreements, adjust to changing threats, and sustain 

ties between states after the U.S. and foreign leaders negotiating the 

initial terms leave office, the United States and a number of allies and 

partners have established formal consultative mechanisms to discuss and 

resolve defense issues. These mechanisms can take various forms, to 

include permanent council bodies tasked with addressing alliance 

matters, the establishment of annual meetings between high-level 

defense officials, and the creation of ad-hoc groups of subject matter 

experts tasked with addressing a specific, pressing national security 

challenge.

The smooth functioning of these mechanisms is important for 

extending deterrence against potential adversaries of U.S. allies and 

partners. These adversaries are likely to observe regular U.S.-allied 

consultations and conclude it will prove difficult to politically or 

militarily fracture security relationships that become stronger and closer 

over time. In addition, they may also conclude that decisions reached by 

U.S.-allied defense councils aligning defense plans and processes (such 

as agreements to procure and train with interoperable systems) will put 

them at a distinct disadvantage in future conflicts by fostering the 

development of a combined, well-coordinated U.S.-allied military force. 

Consultative mechanisms are also important to allied and partner 

assurance, providing forums for these actors to directly interact with U.S. 

officials on a range of defense issues and allowing them to communicate 

their views regarding how the United States can best work with them to 

jointly ensure their defense. Public statements following these meetings 

reaffirming the importance of specific security commitments (such as 

pledges regarding an ally’s coverage by the U.S. “nuclear umbrella”) can 

also ease allied concerns regarding emerging threats.37 Moreover, by 

encouraging detailed discussions of issues beyond the views exchanged 

during brief interactions between national leaders, bilateral consultations 

can address many of the critical nuts-and-bolts decisions important to 

combined defense plans and operations. 

For strategists and planners, the decisions and agreements 

reached during U.S.-allied consultations are critically important to

ensuring strategies, plans, and operations developed to deter potential 

adversaries are also tailored to address the assurance needs and requests 

of allies and partners. Allies and partners, for example, can offer key 

insights into the mindsets of potential adversaries that U.S. strategists 

and planners may find vital to the development of effective deterrence 

strategies.38 
20

The results of U.S.-allied talks may also reveal, however, that 

threats the United States views as secondary in importance are 

considered critical or even existential threats by allies and partners. 

While the work of resolving these differences begins with U.S. and allied 

diplomats and defense officials at the negotiating table, bridging these 

gaps will also require specific military advice regarding what forces can 

be brought to bear against a particular threat. Civilians will also turn to 

their military counterparts with questions regarding combined command 

arrangements, combined operations, and other alliance military matters 

that may emerge as key aspects of assurance during closed-door 

deliberations. It is vital for the purpose of assuring allies that the verbal 

or written agreements reached during defense consultations ultimately 

take the form of plans and operations capable of mobilizing troops and 

equipment. 

Example of Consultative Mechanism. The U.S.-ROK Security 

Consultative Meeting (SCM) is regularly held between the U.S. 

Secretary of Defense and ROK Minister of Defense, occurring annually 

or biennially. First initiated in 1968, the SCM is an established 

mechanism for the two allies to address high-level defense matters, to 

include questions regarding U.S. extended deterrence strategies for the 

DPRK. As Secretary of Defense Robert Gates stated in a press 

conference following the 42nd SCM in 2010:

North Korea’s nuclear and conventional-weapons threat 

continues to be the focal point of our alliance’s deterrent 

and defense posture. We are committed to providing 

extended deterrence using the full range of American 

military might, from our nuclear umbrella to 

conventional strike and ballistic-missile defense.39

The 42nd meeting of the SCM also concluded an agreement to 

develop an additional “cooperative mechanism” to focus on discussing 

issues of extended deterrence.40 This led to the formation of the USROK Extended Deterrence Policy Committee, a consultative body that 

allows additional discussion and close cooperation on a range of 

questions regarding nuclear and other forces critical to deterring the 

specific threats faced by the ROK. This body is currently responsible for 

the development of a “tailored bilateral deterrence strategy” through 

table-top exercises and other activities.41

Visible Engagement (Combined Exercises). U.S. forces have 

long conducted combined exercises with allied and partner military 

forces. Through combined maneuvers, simulated combat operations, and 
21

collaboration between headquarters, these exercises provide valuable 

experience to all the militaries involved, allowing them to fight together 

against a common enemy within a future conflict.42

Combined exercises are recognized as an important element of 

allied assurance. For many allies and partners, they demonstrate the 

United States is willing to prepare for the possibility of fighting 

“shoulder to shoulder” with an ally or partner’s military forces in a future 

armed conflict.43 Many U.S. friends abroad also believe the opportunity 

to conduct training operations alongside U.S. armed forces improves 

their own defense capabilities. 

Combined exercises also play a valuable role in extending 

deterrence. They provide a clear regional display of U.S. military power, 

often involving forces sufficient to critically damage or even defeat the 

conventional forces fielded by the potential adversaries of allies and 

partners. Over time they can also demonstrate the increasing 

interoperability between U.S. and allied military forces, presenting 

potential adversaries with the challenge of facing a robust regional 

competitor backed by a superpower. 

For strategists and planners, combined exercises can provide 

opportunities to directly prepare for potential combat scenarios. They 

also serve as invaluable opportunities to better understand allied and 

partner capabilities and test combined command-and-control 

arrangements. Beyond their value in honing combined operations, 

however, strategists and planners must also recognize the potential 

geostrategic impact of any combined exercise. Any visible combined 

demonstration of U.S.-allied military power overseas will be closely 

observed by all parties within the region in question, with its timing, 

operations, and capabilities viewed as potential signals to other states. 

The United States should be prepared for the possibility that potential 

adversaries of U.S. allies and partners may respond to combined 

exercises with inflammatory rhetoric or even hostile acts against 

participating states. 

Example of Combined Exercise. Following the sinking of the 

ROKS Cheonan, the United States agreed to send the aircraft carrier USS 

George Washington to participate in a maritime and air exercise with the 

ROK titled “Invincible Spirit.” In a joint public statement announcing 

the exercise, U.S. Secretary of Defense Robert Gates and ROK Defense 

Minister Kim Tae-young described the deterrence signal it would send to 

DPRK:

[T]hese defensive, combined exercises are designed to 

send a clear message to North Korea that its aggressive 
22

behavior must stop, and that we are committed to 

together enhancing our combined defensive 

capabilities.44

Invincible Spirit represented a combined exercise specifically 

designed to address a regional defense crisis. An example of a regularly 

scheduled combined exercise that provides assurance to U.S. allies by 

strengthening interoperability and cooperation between forces is the 

“Rim of the Pacific” (RIMPAC) exercise, a major air, naval, and 

amphibious forces exercise hosted by the United States every two years. 

RIMPAC 2012, for example, included armed forces from 22 states and 

featured operations conducted by 40 ships and 200 aircraft.45 At the 

conclusion of the exercise, Admiral Cecil Haney, commander, U.S. 

Pacific Fleet, noted “The partnerships, cooperation and camaraderie 

forged during this exercise are essential to the promotion of peace in the 

Pacific region and will be invaluable during future contingencies, 

wherever and whenever they might be.”46 Participating forces also noted 

the exercise’s importance in allowing states to “share understanding of 

operational level planning,” engage in combined training drills, and learn 

about allied and partner defense capabilities.47

Basing Arrangements and Rotations. During the Cold War, a 

number of U.S. allies offered to host permanent bases for U.S. 

conventional forces (joined in some cases by nuclear forces) on their 

home territory, convinced any attack against them resulting in the loss of 

American life would provoke a swift military response by the United 

States against the aggressor. 

In the present era, U.S. troops based or regularly rotated abroad 

continue to play a key role in assuring allies and partners.48 Although 

U.S. allies and partners do not currently face a superpower threat akin to 

that posed by the Soviet Union during the Cold War, many remain 

convinced the presence of U.S. “boots on the ground” on their home 

territory remains a powerful defense against a range of potential 

adversaries and threats.49 If these forces are threatened or attacked, they 

believe the United States will mobilize the full force of a military 

superpower to dismantle the attacker and effectively secure their state 

and region. 

The regular rotation of U.S. forces within a country or region, or 

the temporary forward deployment of U.S. forces to an allied or partner 

state, also has value for the purposes of assurance. Although 

representing a less permanent commitment than basing, these actions can 

allow the United States to regularly, visibly reaffirm security guarantees 

and quickly respond, as necessary, to emerging threats or sudden 
23

provocations against its friends abroad. These deployments may also be 

an ideal option for security partners who – for political or cultural 

reasons – are unable to host a fixed U.S. military facility on their home 

territory.

U.S. bases are also a highly effective deterrent to potential 

adversaries of U.S. allies and partners. The permanent presence of U.S. 

forces in theater forces these actors to take into account the potential U.S. 

involvement in any local conflict they initiate, particularly if their plans 

include an attack on a nation hosting U.S. military facilities. 

The decision to establish a base on foreign territory, expand 

existing facilities, or forward deploy troops abroad, is often negotiated 

and resolved at the highest political levels of the United States and an 

ally or partner. Policymakers concluding these agreements, however, 

will seek advice from strategists and planners regarding what types of 

forces should be posted to the territory of an ally or partner. Bases 

represent long-term, resource-intensive investments by the United States 

and the host nation.50 The United States must look beyond the short term 

to determine what types of facilities and forces can best address a range 

of evolving regional threats, while also seeking to minimize vulnerability 

to potential future adversary capabilities. In order to make the best use 

of available resources, planners must balance the advantage of having 

forces close to potential threats against the reality that forces based in 

region X may be unavailable – or very difficult to shift – to region Y.

Example of Regular Rotation. In November 2011, the United 

States and Australia announced an agreement to expand the two states’

defense relationship through major rotational deployments of U.S. 

Marines to military facilities and training areas in Australia’s Northern 

Territory. In announcing the agreement, President Obama stated the 

deployments would “strengthen the security of both of our nations” while 

also “send[ing] a clear message of our commitment to this region.” He 

also linked the decision with his administration’s determination to 

“rebalance” U.S. national security strategies and resources toward the 

Asia-Pacific.51 For Australia, Prime Minister Julia Gillard presented the 

agreement as an important opportunity to strengthen the two countries’ 

60-year military alliance and noted that one of its benefits was an 

increase in joint training between the U.S. and Australian armed forces. 

In addition, she also cited the role of America as a “force for stability” in 

the Asia-Pacific as an important reason for Australia to agree to host 

regular rotations of U.S. Marines.52
24

Military Capability

The 2010 Quadrennial Defense Review states that fielding 

“dominant” military forces capable of projecting power across the globe 

is essential to the “integrity of U.S. alliances and security partnerships.”53

Within a diffuse and dangerous 21st century geopolitical environment, 

the effectiveness of U.S. extended deterrence and assurance strategies 

relies on foreign actors – allies, partners, and their potential adversaries –

believing the U.S. military is capable of quickly and decisively defeating 

any potential opponent of a U.S. friend abroad. This is particularly 

important in terms of potential adversaries armed with WMD, as U.S. 

allies and partners (particularly those without nuclear or other WMD) 

rely heavily or completely on the United States to destroy or neutralize 

these weapons before they can cause serious harm. 

Key requirements of extended deterrence and assurance include, 

but are not limited to, military forces with superior combat power, 

flexibility, mobility, and the ability to conduct stand-off and long-range 

strikes.54 The depth and breadth of characteristics required for forces 

assigned to protect allies reflects the reality that assuring allies and 

extending deterrence against their enemies involves operations carried 

out far from home. Moreover, U.S. military forces deployed abroad 

rarely have the luxury of focusing on one mission; they may be required 

to simultaneously deter a range of adversaries while also shielding a 

diverse network of allies with widely varying security needs. 

Furthermore, U.S. forces must also maintain a high degree of visibility to 

all parties in areas of vital strategic interest in order to deter and dissuade 

anti-area/access denial efforts. In many important regions, the U.S. 

military is the only actor capable of protecting key aspects of the “global 

commons;” for example, U.S. naval and air platforms are often the only 

available options for operations ensuring the safety and freedom of 

international waters and airspace, missions that are critically important to 

the economic health and national security of both the United States and 

its allies.55

As a result, extended deterrence and assurance guarantees place 

requirements across the full spectrum of U.S. military power. Strategies, 

plans, and operations for protecting allies and partners from foreign 

threats require the utilization of conventional, missile defense, and 

nuclear forces, with additional support provided by space and cyber 

enablers. 

Conventional Forces. During the Cold War, nuclear forces were 

often the focus of U.S. extended deterrence concepts and strategies. 
25

While nuclear forces remain critical to extended deterrence and 

assurance today, they play an increasingly narrow role within U.S. 

defense strategy.56 This reduced emphasis on the U.S. nuclear arsenal 

highlights the central importance of U.S. conventional forces to the 

deterrence of adversaries and the protection of allies and partners 

abroad.57 

U.S. conventional forces are critical to extended deterrence, 

representing the principal means by which the United States responds to 

provocations or attacks that threaten to either harm its friends or 

destabilize key strategic regions abroad. Extending deterrence globally 

poses a number of challenges to any military force, including that of a 

superpower. For the United States to effectively deter foreign actors 

distant from the continental United States (CONUS), these actors must 

believe the U.S. military is capable of conducting rapid, accurate, and 

effective attacks without imposing unacceptable risks to its own security. 

The long-range strike and stand-off capabilities of U.S. conventional 

forces, together with other advanced qualities that permit operations in 

risky or degraded environments, allow the United States to develop and 

employ deterrence strategies against potential opponents of allies and 

partners in vital regions far from CONUS.58 As recently demonstrated 

by Operation Odyssey Dawn, the United States must maintain military 

forces capable of launching accurate, devastating strikes into geographic 

areas where it has no permanent bases, as circumstances may require the 

rapid elimination of key adversary military assets in the initial phase of 

combat operations in order to protect allied forces (and, in this case, the 

civilian populations Libyan rebels were attempting to protect).59 

Indeed, with the 2010 QDR noting the United States “remains 

the only nation able to project and sustain large-scale operations over 

extended distances,” the U.S. military is currently the only force capable 

of putting into practice extended deterrence strategies featuring 

conventional forces.60 While scholars and analysts continually debate 

whether potential adversaries view the potential use of U.S. nuclear 

weapons for extended deterrence as a credible threat, there is little doubt 

among foreign governments regarding the lethal capabilities of U.S. 

conventional forces.61 The present advantages enjoyed by U.S. 

conventional forces, however, act as a key driver for a number of 

unconventional weapons programs by potential adversaries. Several 

have essentially accepted they cannot hope to win any near-term 

conventional military-to-military conflict where the United States 

intervenes on behalf of its allies or partners, prompting them to seek 

WMD capabilities in order to deter the conventional might of the United 

States. 
26

U.S. conventional forces are also essential to assuring allies and 

partners. In addition to the latter’s persistent belief in the value of 

hosting U.S. boots on the ground, U.S. conventional forces are more 

mobile and adaptable than other U.S. military assets. Their ability to 

quickly respond to threats against allies and partners is important to 

calming allies anxious for a visible, tangible sign the United States is 

prepared to sacrifice blood and treasure on their behalf. The ability to 

rapidly dispatch carrier groups, bomber wings, combat brigades, or other 

U.S. military forces anywhere in the world has repeatedly allowed the 

United States to assure allies and partners that they are protected – and in 

many cases, prevent the latter from undertaking destabilizing actions of 

their own. 

The implementation of many extended deterrence and assurance 

strategies, plans, and operations relies heavily upon U.S. conventional 

forces. Strategists and planners should understand, however, that the 

deployment or use of U.S. conventional forces to assure an ally or deter 

an enemy may prompt the latter to contemplate the deployment or even 

use of unconventional forces to attempt to counter the United States. For 

example, some adversaries may view the deployment of U.S. 

conventional forces near their territory as placing their WMD arsenals –

potentially their only trump card against the United States – at risk, 

forcing them to bolster these weapons’ defenses, move them, or even 

consider their use early in a conflict. Other potential adversaries of U.S. 

allies may believe unconventional attacks are the only means to delay or 

halt the U.S. military from quickly responding to defend a beleaguered 

ally. 

Strategists and planners should also recognize that, for the 

purposes of assurance, U.S. military forces stationed abroad are viewed 

as highly credible and reliable by the allies or partners permanently or 

regularly hosting these troops – but in many cases, they are also assumed 

to represent a “trip wire” initiating a much larger U.S. response in the 

event they are attacked. 

 

Example of Conventional Forces (Extended Deterrence). In 

June-July 2012, in response to a number of Iranian threats against U.S. 

allies, partners, and the free navigation of the Persian Gulf, the United 

States significantly increased the number of U.S. naval and air forces 

deployed to the Middle East. These moves were expressly intended to 

achieve a number of regional assurance and extended deterrence 

objectives. The United States sought to assure friendly states concerned 

by Iran’s increased bellicosity that Tehran could not prevent the 

deployment of U.S. military forces capable of quickly overwhelming any 
27

Iranian attempt to harass or halt shipping in the Persian Gulf. 

Furthermore, the United States sent capabilities tailored to effectively 

deter specific Iranian naval threats to U.S., allied, and international 

shipping, such as the use of mines or small “fast attack” boats. A U.S. 

defense official involved in planning the deployment bluntly noted in a 

newspaper interview:

The message to Iran is, ‘Don’t even think about it .... 

Don’t even think about closing the strait. We’ll clear the 

mines. Don’t even think about sending your fast boats 

out to harass our vessels or commercial shipping. We’ll 

put them on the bottom of the Gulf.62

Nuclear Forces. The slow but ongoing proliferation of nuclear 

weapon technology, and the determination of states of concern such as 

Iran and North Korea to develop and field their own nuclear forces, 

represent critical threats to the United States and to its friends abroad. 

Even as the overall role of nuclear weapons in U.S. national 

security strategy is reduced, nuclear forces remain an essential element 

of extended deterrence and assurance strategies.63 Potential adversaries 

of U.S. allies and partners develop and field nuclear weapons in order to 

assert regional hegemony, intimidate neighbors, and present an 

existential threat to their potential opponents – to include the United 

States. When facing a nuclear-armed opponent, nuclear weapons remain 

the only effective deterrent against nuclear attack. 

Extending deterrence against regional risk-taking states in 

possession of limited nuclear arsenals – or determined to develop these 

weapons – requires the United States to clearly demonstrate it possesses 

nuclear forces capable of imposing “unacceptable costs” against any 

actor contemplating a nuclear attack against a U.S. ally or partner.64 

While each leg of the U.S. nuclear triad possesses this capability, 

nuclear-capable aircraft (bombers and dual-capable aircraft (DCA)) are 

particularly important to extended deterrence against this type of 

opponent. In response to nuclear saber-rattling by a risk-taking state with 

a limited nuclear arsenal, the United States can rapidly fly these delivery 

systems into the region in question, showing this state – and local U.S. 

allies – that it can immediately respond to any provocation with superior 

nuclear capabilities.65

U.S. nuclear forces are also essential to the assurance of allies 

and partners. Other than the United Kingdom and France, no U.S. ally or 

partner openly possesses their own nuclear arsenal. As a result, many 

allies and partners are entirely dependent upon the United States for the 

provision of a nuclear deterrent against potential adversaries armed with 
28

nuclear weapons. The importance of this fact – which is a day-to-day 

reality for many U.S. friends abroad – cannot be overemphasized; for 

these states, the only weapon they view as fully effective against nuclear 

coercion or attack is not in their possession.66 This highlights the 

importance of the U.S. “nuclear umbrella” to nuclear nonproliferation 

efforts; it is vital for the United States to convince allies and partners 

they have no need to consider developing their own, independent nuclear 

deterrent.67

Within the U.S. nuclear arsenal, allies and partners particularly 

value visible and mobile U.S. nuclear forces.68 As noted above, within 

current U.S. nuclear forces these characteristics are associated with 

nuclear-capable aircraft. U.S. allies and partners recognize the United 

States can also deliver nuclear payloads globally with submarinelaunched ballistic missiles (SLBMs) and intercontinental ballistic 

missiles (ICBMs). Many find greater assurance, however, in forces they 

can directly observe stationed or forward deployed on their territory, or 

regularly rotating in theater. They also share the U.S. conviction that the 

rapid, visible generation or deployment of U.S. nuclear forces can 

prevent nuclear-armed potential adversaries from engaging in nuclear 

brinkmanship. 

Planners and strategists must demonstrate to allies, partners, and 

potential adversaries that U.S. nuclear forces are not solely restricted to 

central deterrence. Potential adversaries must also recognize that the 

United States is capable of rapidly matching any type of nuclear 

provocation or escalation. In addition, U.S. strategists and planners need 

to balance allied requests for nuclear forces sufficient to deter and defeat 

prospective opponents against allied concerns regarding the potential 

consequences of nuclear conflict (such as fallout drifting across their 

borders). At present, due to the threats posed by risk-taker states, the 

role of nuclear airpower is critically important to a range of U.S. 

extended deterrence and assurance strategies. As such, strategists and 

planners must understand the unique (and differing) capabilities and 

requirements of bombers, DCA, and the warheads they can deliver. 

Example of Nuclear Forces (Extended Deterrence and Allied 

Assurance). By rotating aircraft from CONUS to Guam, U.S. Air Force 

B-2 and B-52H long-range nuclear-capable bombers maintain a 

“continuous presence” in the Pacific. The use of these rotations for 

extended deterrence and assurance purposes began in 2003 after the 

deployment of U.S. forces to Iraq. They were intended to assure regional 

allies and deter potential adversaries by visibly demonstrating to all 

regional actors that the deployment of significant forces to the Middle 
29

East would not curtail the U.S. ability to project power into a second 

vital strategic theater.69 The aircraft continue to serve a dual “deter and 

assure” mission today.70 By visibly deploying nuclear-capable forces 

into a region with three other nuclear powers (China, Russia, and the 

DPRK), “continuous presence” signals to all key players within the 

region the United States is committed to extending a nuclear umbrella 

over its friends – and stands prepared, if necessary, to use nuclear forces 

against their enemies. 

Missile Defenses. U.S. theater missile defenses first played a 

significant assurance role during Operations Desert Shield/ Desert Storm, 

when Patriot batteries were deployed to protect U.S. troops and allies in 

the Middle East.71 Today Patriot Advanced Capability (PAC-3)

batteries, Aegis systems, and other components of U.S. theater missile 

defenses play an increasingly prominent role in regional defense 

architectures. 

U.S. missile defenses extend deterrence against potential 

adversaries of allies and partners by counteracting ballistic missiles, a 

key weapon within the arsenals of regional states of concern. Missile 

proliferation in the post-Cold War era has provided a number of states 

with otherwise limited military capabilities a relatively inexpensive 

delivery system for threatening regional neighbors with either 

conventional or unconventional strikes. By providing a defense system 

that can neutralize ballistic missile attacks, U.S. theater missile defenses 

allow the United States to implement deterrence by denial strategies on 

behalf of allies and partners. 

Missile defenses are also vital to assurance, as a number of U.S. 

allies and partners face potential adversaries that possess ballistic missile 

arsenals, WMD programs, and a track record of taking risks to coerce or 

attack neighbors.72 Against this type of adversary, allies and partners 

may fear that an advantage in conventional forces alone will prove 

insufficient to extend deterrence against actions such as ballistic missile 

strikes. Effective theater missile defenses, however, can assure U.S. 

allies and partners they are shielded from these types of attacks. 

Moreover, missile defenses also show U.S. allies and partners that 

ballistic missile threats will not deter the United States from intervening 

on their behalf, nor will adversary missile attacks significantly degrade 

U.S. military operations in theater.73 Furthermore, by combining theater 

missile defenses with offensive strike capabilities, the United States can 

show allies it possesses the capability to both neutralize the weapon of 

choice of potential adversaries while also conducting a range of strikes 

that will quickly defeat an opponent’s land, air, and naval forces. 
30

For strategists and planners, theater missile defenses provide a 

capability to counter opposition ballistic missile arsenals – as noted 

above, a key weapon for several adversaries who recognize they cannot 

match the conventional strength of the United States and its allies and 

partners. Missile defenses are also an important component of any force 

package assembled for assurance purposes in response to provocations 

such as ballistic missile tests by a potential adversary that terminate 

outside of their national territory. Beyond crises and conflicts, theater 

missile defenses are also critical to the construction of long-term regional 

defense architectures. An enduring goal of U.S. strategies, plans, and 

operations abroad is to present both friend and foe with a seamless 

offense-defense, deterrence-by-punishment and deterrence-by-denial 

combination of forces. Missile defenses can play an important role in 

leading foreign actors to conclude ballistic missile threats will not 

dissuade the United States from intervening on behalf of an ally. 

Furthermore, when regionally deployed by the United States, and/or 

networked with allied missile defenses, these capabilities may also 

convince potential adversaries that U.S. allies and forward deployed 

forces are effectively shielded from ballistic missile attacks. 

Example of Missile Defenses (Allied Assurance). For decades, 

the DPRK has directed bellicose rhetoric against Japan, reflecting both 

the bitter legacy of Japan’s occupation of Korea during the Second 

World War and Tokyo’s close alliance with the United States. In recent 

years, the DPRK has conducted several ballistic missile tests with 

trajectories that carried the systems either toward or over Japan. With 

the DPRK also widely believed to possess a small nuclear arsenal, Japan 

views Pyongyang’s ballistic missile forces as a direct threat to its 

national security.74

In response to the DPRK’s missile tests, the Japanese 

government decided in 2006 to pursue – “with a sense of urgency” –

close cooperation with the United States on missile defenses.75 Missile 

defenses are now integral to the U.S.-Japan alliance, with the two states 

working together to jointly fund, develop, and test systems such as the 

Standard Missile 3 (SM-3) Block II-A interceptor.76 Japan also 

purchased and now fields the Aegis missile defense system on several of 

its naval destroyers.77 In addition, it hosts U.S. missile defense 

interceptors and key enabling systems such as AN TPY-2 radars.78

Missile defenses are essential to U.S. assurance of Japan. They 

grant Japan a degree of protection against the DPRK’s missile arsenal, 

which in combination with its nuclear weapons program has led Tokyo 

to conclude Pyongyang represents an immediate, pressing security threat. 
31

The ability of missile defenses to protect U.S. forces in the Pacific from 

ballistic missile attack, allowing the United States to conduct operations 

in theater despite the threat posed by the DPRK’s missiles, is also acutely 

important to the assurance of Japan. While Japan’s Self-Defense Force 

is a capable military force, constitutional law, historical norms, and other 

factors limit its ability to conduct major offensive strikes against foreign 

states. The Japanese government and Japanese defense analysts thus 

stress the importance of missile defenses to the country’s national 

security in part due to their ability to strengthen the deterrent value of 

regionally based U.S. military forces, allowing its ally to swiftly attack 

and eliminate these missile capabilities without fear of reprisal against 

either their facilities in Japan or its home territory.79

Tailoring Extended Deterrence and Assurance Strategies 

The framework presented in Figure 1.1 is intended to 

communicate the critically important concept that assuring allies, and 

extending deterrence against their potential adversaries, requires the 

United States to carefully tailor policies, strategies, and plans combining 

effective military capabilities with clear demonstrations of political 

resolve. This requires national leaders, policy makers, diplomats, 

intelligence analysts, defense strategists, and military planners to work 

together to ensure the seamless integration of U.S. extended deterrence 

and assurance strategies and policies – despite their differing 

requirements. Moreover, it also requires all of these U.S. actors to 

understand that any changes to these strategies and policies – to include 

perceived changes – can have a ripple effect affecting the cost-benefit 

calculations of numerous U.S. allies and/or their potential adversaries. 

This reflects the central importance of U.S. extended deterrence and 

assurance strategies to the security of allies and the strategizing of their 

opponents. It also throws into sharp relief the degree of difficulty 

associated with tailoring these strategies for individual actors within a 

complex, dynamic geopolitical environment.
32
33

PART 3: DETERRENCE, EXTENDED DETERRENCE, AND ALLIED 

ASSURANCE FROM THE COLD WAR TO THE WAR ON TERROR 

(1945-2008)

Continuity and Change in U.S. Deterrence, Extended Deterrence, 

and Assurance Concepts

Across the Cold War and into the 21st century, the United States 

has committed itself to the protection of allies around the globe, viewing 

the defense of friendly regimes as critically important to its own national 

security. As a result, for decades the United States has invested 

significant amounts of diplomatic and military capital, to include 

permanent deployments of large numbers of troops overseas, in order to 

encourage the stability of key strategic regions and protect its friends 

from their potential adversaries. For the United States, many of the 

general geopolitical principles and national security policy imperatives 

underlying its efforts to assure allies and extend deterrence against their 

enemies have remained largely unchanged over time. The development 

and implementation of extended deterrence and assurance strategies, 

plans, and operations, however, have adapted and evolved to reflect 

major geopolitical changes, the development of new military capabilities, 

fluctuation in the number and types of U.S. adversaries and allies, and 

other factors. 

This section provides a historical survey of deterrence, extended 

deterrence, and assurance concepts and strategies from the early stages of 

the Cold War to the eve of the Obama administration. Given the 

preponderance of literature on NATO during the Cold War, the focus is 

on NATO and Europe rather than other regions of the world in which the 

United States provided extended deterrence guaranties such as East Asia 

and the Middle East. This chapter analyzes this history in order to 

determine general trends in the strategies and forces associated with 

extended deterrence and allied assurance, and closes with an assessment 

of the enduring challenges U.S. policymakers and strategists face in 

ensuring that U.S. defense guarantees remain credible in the face of 

geopolitical change, shifts in U.S. defense priorities, and questions in 

foreign capitals (both allied and adversary) regarding U.S. commitments 

overseas. 

Cold War Deterrence

During the long Cold War confrontation with the Soviet Union 

and its proxies, the United States faced a number of fundamental 
34

challenges in developing effective deterrence, extended deterrence, and 

assurance strategies. 

First, the Soviet Union represented a formidable military 

adversary. Just four years after the United States used nuclear weapons 

against Japan to hasten the end of the Second World War, the Soviet 

Union conducted its own successful atomic test. While initially lagging 

behind the United States in delivery system and warhead development, 

the Soviet Union eventually caught up with its rival and surpassed it in 

terms of numbers of fielded and stockpiled nuclear forces. The Soviet 

Bloc also enjoyed a significant advantage over the United States in 

numbers of soldiers and stocks of military equipment, a mismatch that 

left American strategists with limited and unpalatable options for 

developing a credible defense against a major conventional attack aimed 

at Western Europe or other vulnerable allies. 

Second, as the leader of the “free world,” the United States 

found itself attempting to defend friendly regimes scattered across the 

globe. These allies varied widely in terms of their defense capabilities 

and their views on how to address the Soviet threat, complicating U.S. 

efforts to mount a coherent common defensive strategy against Moscow. 

Third, throughout the Cold War the United States had to 

convince allies it would not abandon them in the event of Soviet 

aggression backed by implicit or explicit nuclear threats. U.S. 

policymakers and strategists also found themselves repeatedly addressing 

allied concerns that U.S. capabilities devoted to their defense were 

insufficient for deterring Moscow. 

These challenges – mitigated, but never fully resolved, by U.S. 

technological advances – shaped U.S. deterrence, extended deterrence, 

and assurance strategies across the Cold War.

Early Cold War: Massive Retaliation. In the first years of 

the nuclear age, the United States had a monopoly on nuclear 

weapons. Initially its arsenal was small, but the fact that it was 

the only state to successfully harness the power of the atom 

was militarily and psychologically significant, providing a 

powerful form of assurance to allies early in the Cold War. 

Although the Soviet Union soon developed its own nuclear 

capability, and went on to match the United States in 

successfully designing and testing thermonuclear weapons, 

during the 1950s the U.S. military enjoyed a significant 

quantitative and qualitative edge in nuclear forces. The 

strategic balance between the superpowers was much 
35

different, however, in regard to other types of forces. After the 

Second World War the Soviet Union continued to field massive 

land, naval, and air forces at levels that the United States could 

not match. In addition, the Korean War demonstrated 

shortcomings in America’s peacetime armed forces and the 

vulnerability of distant allies with limited military capabilities. 

Dissatisfied with the Truman administration’s handling of the 

Korean War and its broader foreign and security policies with regard to 

the challenges posed by global Communism, President Eisenhower came 

to office in 1950 determined to take a “New Look” at U.S. geopolitical 

strategy, to include a reexamination of the military means required to 

defend the United States and its friends from the massive conventional 

forces of the Soviet Union and its proxies. At the same time, however, 

Eisenhower was concerned that any strategy forcing the United States to 

indefinitely maintain heightened levels of defense spending would 

ultimately sap the nation’s economic strength. President Eisenhower 

expressly directed his National Security Council to develop “a 

reasonable and respectable posture of defense ... without bankrupting the 

nation.”80 The United States needed to invest in capabilities that could 

offset this disadvantage in conventional forces without breaking the 

budget. In addition, the United States needed to field capabilities that 

would allow it to quickly and decisively exact significant costs on the 

Soviet Union in the event of armed provocation. The Soviets had proved 

they could keep fighting despite absorbing fantastic costs in terms of 

personnel and resources, and that it could win a brutal, drawn out war of 

attrition. This led Eisenhower’s National Security Council to conclude 

the United States needed to rapidly develop “a strong military posture, 

with an emphasis on the capability of inflicting massive retaliatory 

damage by offensive striking power” in order to deter the Soviet Union.81

Eisenhower’s national security team believed nuclear forces –

which at the time were cheaper to build and deploy than permanently 

stationing large numbers of conventional military forces around the 

globe – were the answer. The president and his advisers concluded that 

emphasizing nuclear weapons, an area in the 1950s where the United 

States enjoyed a distinct advantage over the Soviet Union in delivery 

systems, warheads, and production capabilities, represented the best use 

of scarce defense dollars to develop an effective deterrent against Soviet 

aggression. They were also the only weapon within the U.S. arsenal 

capable of threatening the Soviet Union with “massive retaliatory 

damage” in the event it attempted to attack the United States or its allies. 

The Eisenhower administration also hoped that increasing the U.S. 
36

nuclear arsenal would allow it to significantly cut back on other military 

expenditures, to include drawing down the number of U.S. conventional 

forces deployed abroad. It subsequently invested heavily in a broad 

range of nuclear weapons; in addition to significantly boosting existing 

numbers of long-range nuclear-capable bombers, the United States also 

increased research, development, and deployment of a wide variety of 

short-range nuclear delivery systems expressly intended for defending 

the free world’s defense perimeter.82

U.S. strategists also developed military doctrines and war plans 

that attempted to take advantage of the country’s superiority in nuclear 

forces. U.S. deterrence strategy in the early years of the atomic age thus 

relied on threatening the Soviet Bloc with “massive retaliation” in 

response to an attack on the United States or its allies. Core deterrence 

took the form of aerial bombardment using nuclear weapons, the ultimate 

form of deterrence by punishment. The bombers of the U.S. Air Force’s 

Strategic Air Command (SAC) would strike at the cities in the center of 

the Soviet motherland, destroying the Soviet Union, its industries, and 

most of its population, in one paroxysm of violence – what SAC planners 

called a “knock-out preemptive blow.” Initially reliant upon aircraft 

mounting attacks from bases abroad, SAC was later equipped with 

bombers that, with tanker assistance, possessed intercontinental range. 

In time, SAC would develop and implement plans to keep bombers aloft 

24 hours a day, ready at a moment’s notice to launch a major nuclear 

attack on targets across the Soviet Union.83

The strategy of massive retaliation reflected both an assessment 

that only the threat of massive punishment could deter the Soviet Union 

and the military technology of the era. With the US nuclear force reliant 

on bombers carrying unguided gravity bombs, factors such as possible 

attrition from enemy air defenses, the requirement to use multiple bombs 

to assure the destruction of a target, and the relatively limited intelligence 

available on key military targets (to include adversary nuclear forces and 

stockpiles) in the pre-satellite era required a strategy using large numbers 

of bombers, large numbers of munitions, and large fixed targets located 

in the Soviet homeland. All of this was meant to deter Moscow from 

contemplating attacks on the United States. 

The strategy of massive retaliation also applied to strategies for 

extended deterrence, with the United States bolstering allied 

conventional forces and U.S. forward-deployed troops with significant 

numbers of U.S. nuclear forces. Eisenhower’s Secretary of State, John 

Foster Dulles, explained that conventional forces, while important to 

U.S. and allied defense, were insufficient to extend deterrence against 

Moscow
37

Local defenses must be reinforced by the further 

deterrent of massive retaliatory power .... Otherwise, for 

example, a potential aggressor, who is glutted with 

manpower, might be tempted to attack in confidence that 

resistance might be confined to manpower.84

In order to ensure that a potential aggressor could not rely on a U.S. 

response remaining restricted to conventional forces, the Eisenhower 

administration deployed nuclear-capable delivery systems, from longrange bombers to short-range artillery, to directly support U.S. 

conventional forces engaged in the local defense of U.S. allies. U.S. 

declaratory policy for these nuclear forces remained deliberately vague, 

with Dulles explaining, “[i]t should not be stated in advance precisely 

what would be the scope of military action if new aggression occurred 

....that is a matter as to which the aggressor had best remain ignorant.”85 

The Eisenhower administration also sought to deliberately blur the line 

between conventional and nuclear operations within theater defense 

plans, with Chairman of the Joint Chiefs Admiral Arthur Radford 

publicly stating in December 1953, “atomic weapons have virtually 

achieved conventional status within our armed forces.”86

Combined with the visible deployment of nuclear systems down 

to very low echelons, these policy and strategy statements were intended 

to signal the Soviet Union and its proxies that any form of incursion over 

allied borders could lead the United States to launch a major retaliatory 

nuclear strike. By leaving their principal opponent in doubt regarding 

the potential use of U.S. nuclear weapons, the Eisenhower administration 

hoped to deter a broad range of aggressive actions against U.S. allies and 

partners abroad.

In addition to extending deterrence against the Soviet Union, the 

United States also hoped the strategy of “massive retaliation” would 

assure U.S. allies, convincing them that U.S. nuclear forces were central 

to their defense and not simply intended to shield the United States. 

Maintaining a direct, visible U.S. nuclear presence in-theater or on allied 

territory was also vital to addressing allied concerns regarding the Soviet 

Bloc’s advantages in conventional forces. The local presence of nuclear 

forces would enhance the assurance value of U.S. conventional forces 

based overseas (and soften the blow of potential U.S. troop reductions). 

Over time, for example, most NATO allies came to accept that the 

primary purpose of U.S. conventional forces in Europe was to serve as a 

nuclear “trip wire.” 87 They were expected to slow – rather than defeat –

the massive armies of the Warsaw Pact in the event of an invasion of 

Western Europe; if Moscow continued to press its war machine forward 

after the initial series of conventional engagements, it faced the 
38

possibility the United States might attempt to blunt its offensive through 

the use of “tactical” battlefield nuclear strikes. 

The adoption of the strategy of massive retaliation was viewed 

by the Eisenhower administration as critical for deterring Communist 

aggression against the United States and its allies given the conventional 

force imbalances favoring the Soviet bloc. Eisenhower and Dulles also 

believed equipping U.S. armed forces with a range of tactical and 

strategic nuclear systems, and deploying nuclear-armed units to both the 

European and Pacific theaters, would reassure allies nervously watching 

the decline in post-Korean War U.S. defense budgets and significant 

drawdowns in the number of U.S. troops deployed abroad. U.S. nuclear 

forces, whether forward deployed or capable of rapidly rotating to 

overseas bases, would serve as a visible demonstration of Washington’s 

willingness to directly commit nuclear weapons to the protection of its 

friends and allies abroad and risk nuclear war on behalf of their 

defense.88

Flexible Response. By the early 1960s, however, U.S. 

policymakers and strategists began searching for viable alternatives to a 

strategy dependent on deterring the Soviet Union with a massive 

outpouring of destruction over any conventional provocation. In 

addition, significant Soviet improvements to its nuclear strike 

capabilities and expansion of its nuclear arsenal put the entire American 

homeland at risk in any future conflict, raising new questions for U.S. 

deterrence and extended deterrence strategies that relied on America 

enjoying a decisive advantage in nuclear forces. Both sides were also 

developing and fielding nuclear forces with intercontinental range, to 

include ground-launched ICBMs (the first U.S. ICBM, the Atlas D, was 

fielded in late 1959) and submarines capable of launching SLBMs, to 

supplement their existing forces of nuclear-capable manned bombers. 

These developments immensely complicated targeting decisions 

and game theoretical approaches to war fighting. If both sides had some 

forces that could survive a nuclear first strike, either could respond by 

hitting the other’s homeland with these remaining “second strike” 

weapons. In an era lacking effective ballistic missile defenses, both 

societies were totally vulnerable to these potential second strikes. U.S. 

strategists realized that even if the United States withheld Soviet cities 

from an initial nuclear strike (in hopes that the enemy would do the 

same), those population centers would be vulnerable to a second strike, 

essentially serving as hostages to intra-war negotiations. 

As a result, some U.S. strategists and policymakers began to 

question whether massive retaliation still represented a credible threat; it 
39

appeared unlikely to achieve its military objectives without enormous 

loss of life on both sides, with costs so high that decision-makers would 

likely dismiss it out of hand. The Soviet Union also appeared willing to 

test the resolve of the United States and its allies by using military and 

security forces to take actions that damaged Western interests – such as 

physically dividing Berlin – in a manner that did not result in shots being 

fired. How could the United States deter limited provocation if its only 

strategy was to counter Soviet aggression with the threat of total nuclear 

Armageddon? 

Forced to consider these questions against the backdrop of a 

series of superpower crises over Berlin and other issues, the John

Kennedy administration became convinced it needed to explore new 

ideas for deterring the global Soviet threat. President Kennedy 

recognized that U.S. nuclear forces remained essential to U.S. deterrence, 

extended deterrence, and assurance strategies. The Soviet advantages in 

manpower and the defense requirements of a globally dispersed set of 

allies could not be addressed by conventional forces alone. He was 

dissatisfied, however, with war plans that left him with little recourse to 

respond to Soviet Bloc incursions or harassment with anything other than 

a major nuclear attack. In response, he directed his national security 

team to develop options for U.S. responses to Soviet provocations in 

Europe and elsewhere that did not begin or end with a massive U.S. 

nuclear attack against a broad range of Soviet targets. Thus began the 

search for more flexible, discrete nuclear options that could deter the 

Soviet Union from attacking the United States or its allies short of the 

threat of an all-out nuclear war. 

Accordingly, the Kennedy administration moved U.S. policy 

away from massive retaliation toward a new concept called “flexible 

response.” This approach, although still dependent on the deterrent value 

of large numbers of nuclear weapons to keep Soviet strategic nuclear 

forces at bay, was designed to provide the United States and its allies 

with a plausible range of conventional and nuclear options for reaction to 

Soviet aggression or provocation short of a resort to a general nuclear 

war. These options sought to match U.S. military capabilities (and the 

potential costs of a conflict) to the level of adversary provocation and 

would, in theory, allow a conflict to remain limited in its early stages.89 

One approach to developing flexible nuclear options for the 

president was selecting targets that did not imply the destruction of the 

adversary’s population – at least not right away. Such an approach might 

emphasize certain adversary targets, such as first and second strike 

nuclear capabilities, economic recovery industries, national leadership, 

command and control locations, and so on. These limited, selective, or 
40

regional attack options would represent alternatives to launching an allout nuclear war that would include strikes on Moscow and other Soviet 

cities – and, it was hoped, grant time for the superpowers to pull back 

from the brink of nuclear Armageddon.90

The concept of assured destruction, however, was not abandoned 

in this new approach to deterrence; in fact, it was embraced by Secretary 

of Defense Robert McNamara as an empirical measure for determining 

force structure requirements for the U.S. nuclear arsenal. Indeed, robust 

nuclear forces were vital to the credibility of U.S. conventional response 

options, as the latent threat of a possible nuclear attack was viewed as 

limiting Moscow’s moves in a crisis or conflict.

Allied Assurance. The development of the flexible response 

concept also attempted to balance competing – and sometimes 

conflicting – requests from American allies, who asked for the protection 

of America’s nuclear umbrella while also seeking assurances from 

Washington that U.S. nuclear forces would never be used in anger. This 

challenge was particularly acute within NATO, whose European 

members were wary of the two superpowers using their territory as either 

a testing- or proving-ground for superpower brinkmanship. NATO states 

feared a “limited” superpower conflict in Europe might leave 

Washington and Moscow intact but devastate their home territories. The 

Kennedy administration’s efforts to press NATO members to decrease 

their reliance on U.S. nuclear weapons by expanding and improving their 

conventional forces, however, met with little success. Allied political 

leaders were wary of increasing defense spending at the expense of 

social and economic programs at home, while their military staffs 

believed nuclear options represented the only way to deter the Warsaw 

Pact. 

The NATO allies, joined by the General Lauris Norstad, the U.S. 

general in command of all alliance forces from 1956-1963, raised two 

major objections to the Kennedy administration’s concept of flexible 

response. First, they argued that any conventional conflict in Europe, 

however limited, was likely to end with the Warsaw Pact in control of 

allied territory. They believed NATO should maintain a policy of 

strongly implying that any adversary attack, however limited, could 

trigger a nuclear response from the alliance. They worried that even 

discussing the possibility of preparing options for fighting a limited 

conflict with limited means might lead the Kremlin to conclude they 

could threaten the alliance – particularly on the European continent –

with little significant or direct risk to themselves. Second, they were 

deeply skeptical of the assumption that two nuclear-armed superpowers, 
41

and their proxies, could effectively limit and manage an escalating 

military crisis. They feared that any limited conventional conflict was 

unlikely to remain either limited or conventional for very long, with 

potentially disastrous consequences for the governments and civilian 

populations of NATO’s European states. 

NATO allies were not in a position to flatly reject the Kennedy 

administration’s ideas on flexible response, and the concept became 

official NATO policy in 1967. The alliance’s Defense Planning 

Committee stated that

The overall strategic concept for NATO should be revised to 

allow NATO a greater flexibility and to provide for the 

employment as appropriate of one or more of direct defence, 

deliberate escalation, and general nuclear response, thus 

confronting the enemy with a credible threat of escalation in 

response to any type of aggression below the level of a major 

nuclear attack.91

The non-U.S. members of the alliance, however, never fully embraced 

flexible response as a substitute for massive retaliation In the 1960s and 

beyond, members of NATO firmly believed the alliance should rely on a 

strong nuclear deterrent to protect Western Europe and to prevent the 

superpowers from seriously contemplating any kind of a land war on the 

continent. Faced with a Warsaw Pact opponent able to call on seemingly 

inexhaustible reserves of manpower, NATO militaries backed the 

alliance’s reliance on a nuclear deterrent largely dependent on U.S. 

strategic and tactical nuclear forces. Moreover, most political leaders of 

NATO states – regardless of their ideological views, and despite the fact 

nuclear forces were often unpopular with their domestic publics –

ultimately accepted nuclear weapons as the only cost-effective means for 

guaranteeing their national security. As a result, both during and after 

the Kennedy administration the concepts of flexible response and assured 

destruction existed side-by-side – not always comfortably – in informing 

U.S. extended deterrence policies and strategies.

Trading New York for Hamburg? The U.S. ability to defend 

Western Europe with nuclear forces capable of deterring a superior 

conventional opponent (and, in time, a nuclear peer) thus represented the 

cornerstone of NATO Cold War defense strategies. It was also vital to 

U.S. efforts to assure each of the alliance’s member states that they 

enjoyed the protection of a nuclear-armed superpower. With the United 

States representing far and away the most powerful member of NATO, 

the cohesion of the alliance depended on member states believing that 

U.S. political leaders were prepared to put their military forces – and
42

perhaps even their homeland – at risk in order to defend allies on the 

other side of the Atlantic. 

As the Soviet Union began developing nuclear forces capable of 

ranging U.S. cities, however, not all U.S. allies were convinced this was 

the case. By the 1960s, President Charles de Gaulle of France was 

openly speculating the United States would never trade New York for 

Hamburg – i.e. it would never risk a Soviet nuclear strike against a major 

U.S. city in order to protect a vulnerable allied target from an attack by 

the Warsaw Pact.92 He also argued that NATO was dangerously 

dependent on the United States and its uncertain (in his mind) nuclear 

deterrent, effectively ceding sovereign decision-making and national 

security decisions to American policymakers in Washington. This, he 

asserted, was extremely dangerous given tensions between the United 

States and the Soviet Union, holding NATO’s European members 

hostage to decisions in foreign capitals. De Gaulle’s doubts about the 

credibility of U.S. extended deterrence commitments to NATO led him 

to strongly support France’s development of an independent nuclear 

deterrent. Neither assured destruction nor flexible response appeared 

credible to him in light of the Soviet Union’s ability to directly threaten 

the United States with nuclear attack. These doubts and his broader 

concerns that France’s membership in the alliance hindered its national 

security and ability to independently engage in Cold War geopolitics 

informed his decision to withdraw France from the NATO’s military 

structure in 1966.93

The questions raised by de Gaulle posed a significant challenge 

to U.S. efforts to assure its European allies as the Soviet Union began to 

develop ICBMs and other long-range nuclear forces.94 By the late 1960s 

Moscow possessed a significant edge in conventional forces and 

appeared capable of credibly threatening the United States, even if its 

overall numbers of forces were still several years from catching up to the 

U.S. arsenal. Some allies wondered if an American president would 

engage in brinkmanship with the Kremlin over Hamburg, Berlin, or other 

vulnerable areas of the alliance. U.S. domestic politics also contributed 

to allied unease in the 1960s, with a number of members of Congress 

voicing their displeasure over what they viewed as a failure of other 

NATO states to shoulder what they considered a fair share of the burden 

of defending Europe.95

The loss of one of its strongest members was a blow to NATO, 

but it remained intact through the end of the Cold War because U.S. 

leaders clearly demonstrated their willingness to risk blood and treasure 

on behalf of Germany and other members of NATO. When France’s exit 

from NATO threatened to leave the alliance homeless and deprive it of a 
43

number of key military facilities, the Johnson administration worked to 

quickly and seamlessly transition NATO’s headquarters from Paris to 

Brussels and U.S. forces stationed in France to the United Kingdom, 

Belgium, and Germany. President Lyndon Johnson also used his skills 

in domestic politicking to head off efforts in the Congress to halve the 

number of U.S. forces in Europe, and ensured the provision of continued 

military and economic support to key NATO members.96

Furthermore, for many European allies de Gaulle’s argument 

that nuclear weapons represented the only true guarantee of national 

security in the superpower era ultimately solidified their commitment to 

NATO. Like de Gaulle, they had become convinced of the importance 

of nuclear deterrence to the defense of their home countries. They 

differed from de Gaulle, however, in their assessment of the U.S. 

commitment to their defense. For most NATO states during the Cold 

War, U.S. conventional and nuclear forces posted to bases on or near 

their home territory provided a visible demonstration of Washington’s 

preparedness to fight for Western Europe. 

In addition, the support of U.S. leaders, beginning with President 

Eisenhower, for NATO “nuclear sharing” arrangements (which would 

make certain types of U.S. nuclear weapons stored in Europe available to 

allies in the event of a major Warsaw Pact attack) also addressed 

concerns the United States would reserve nuclear forces for use only in 

defense of its narrow national interests.97 As aptly summarized by Sir 

Lawrence Freedman in his study The Evolution of Nuclear Strategy, 

most NATO allies during the Cold War “prefer[ed] to live with the 

known uncertainties of the US nuclear guarantee than with the political 

and strategic uncertainties of nuclear independence.”98 Despite 

significant stresses upon the alliance later in the Cold War, after 1966 no 

other states would defect from NATO, and U.S. nuclear forces would 

remain the linchpin of NATO defense strategies and plans until the fall 

of the Berlin Wall. 

De Gaulle’s defection also raised questions about the role of U.S. 

extended deterrence strategies within the broader geopolitics of the Cold 

War. The French president charged that these strategies could actually 

interfere with the development of stable, productive relations between 

European states and the Soviet Union. While disagreeing with de 

Gaulle’s decision to break away from the alliance, other members of 

NATO agreed the alliance needed to determine its views on the 

relationship between deterrence and diplomacy during an era of 

competition between two superpowers and their respective blocs. 

Recognizing the importance of this relationship to assuring its NATO 

allies, the Johnson administration supported Belgian Foreign Minister 
44

Pierre Harmel’s suggestion in late 1966 that the members of the alliance 

conduct a comprehensive study of its first 20 years and use the results to 

assess its future military and diplomatic goals. The initiative was 

recognized as a key effort to rally the alliance in the wake of France’s 

withdrawal and internal disagreements over whether and how to 

diplomatically engage the Soviet Union. The report found that the 

alliance could exercise deterrence and conduct diplomacy at the same 

time, concluding that “military security and a policy of détente are not 

contradictory but complementary.”99 While the Johnson administration 

would have preferred stronger language in support of deterrence, the 

report’s findings generally aligned with the president’s conviction that 

the alliance’s bargaining power was directly linked with its military 

strength:

[a] strong NATO remains essential if we are to reach a solid 

agreement with the Soviet Union that reflects the common 

interests of each of the allied nations in peace and security.100 

The United States’ endorsement of the report and its unanimous 

acceptance by the other members of NATO in late 1967 effectively 

ended questions about the alliance’s viability in the wake of France’s 

departure. It also addressed allied concerns regarding the superpower

relationship. NATO members believed the U.S. nuclear umbrella over 

the alliance was important to their national security. However, they also 

wanted the United States to leave the door open for diplomacy with the 

Soviet Union, arguing that a cold peace with the Soviet bloc was better 

than a hot war that would destroy Europe. As a result, the willingness of 

U.S. leaders in the late 1960s and beyond to stake political capital on 

both the defense of NATO and on diplomacy with the Kremlin was an 

important component of U.S. assurance strategies during the remainder 

of the Cold War.

Supporting Nuclear Deterrence and Arms Control; Rejecting 

Missile Defenses. Most U.S. political and military leaders reluctantly 

accepted deterrence and extended deterrence strategies based on the 

concept of assured destruction as the price of maintaining a stable 

relationship with Moscow and ensuring the defense of U.S. allies around 

the globe. Flexible response provided an alternative approach that 

appeared to broaden the scope of potential U.S. responses to enemy 

provocation to include options below the threshold of a nuclear 

exchange. But the risk of losing control over a limited conflict haunted 

U.S. presidents and strategists alike after the Cuban Missile Crisis. 

The two Cold War superpowers were famously described by J. 

Robert Oppenheimer as “two scorpions within a bottle, each capable of 
45

killing the other, but only at the risk of his own life.”

101 The search for a 

way out of this “bottle” led some U.S. strategists to suggest developing 

sophisticated defense systems capable of shielding the U.S. homeland 

from Soviet ballistic missile strikes. In the 1950s and 1960s the U.S. 

Army sponsored feasibility studies and technology demonstrators aimed 

at developing an anti-ballistic missile that could intercept and destroy a 

ballistic missile in flight.102 These efforts progressed slowly and by the 

mid-1960s did not appear close to offering the prospect of a foolproof 

defense against a Soviet nuclear strike featuring hundreds or thousands 

of missiles. Nevertheless, the development of even a rudimentary 

missile defense system held forth the prospect of some type of limited 

defense against nuclear-armed ballistic missile attacks. In 1967 

Secretary of Defense Robert McNamera announced a decision to deploy 

a missile defense system (“Sentinel”) intended to provide a “thin” 

defense for major U.S. cities against the relatively limited ICBM 

capabilities of China.103

This decision would subsequently lead the Johnson 

administration to hold discussions with NATO allies regarding the 

possibility of deploying missile defenses to Western Europe in the future. 

Allied capitals, however, opposed the idea.104 By the late 1960s they had 

remained under the U.S. nuclear umbrella for nearly two decades, and

had accepted the idea that the threat of mutual assured destruction 

(MAD) ensured strategic stability between the two superpowers. They 

feared missile defense systems might upset this deterrence relationship, 

and concluded they preferred the familiarity of MAD over an unproven 

technology only capable of providing a very limited defense against an 

adversary ballistic missile attack. 

Instead of attempting to find a high-technology solution to the 

existential threat posed by the Soviet Union’s growing nuclear arsenal, 

U.S. allies sought to address this threat through a combination of nuclear 

deterrence – primarily in the form of U.S. nuclear forces, supplemented 

in NATO by British SSBNs and allied DCA – and superpower 

diplomatic negotiations aimed at limiting their numbers of nuclear 

delivery systems and warheads. Within NATO, the allied states 

remained committed to the Harmel report’s recommendation that the 

alliance should present the Soviet bloc with a sword in one hand and an 

olive branch in the other. 

Many U.S. allies also concluded that very large numbers of 

warheads were not necessary to guarantee the credibility of the U.S. 

nuclear umbrella. Those allies that feared their territory might become a 

nuclear battleground between the superpowers, for example, recognized 

that even a limited nuclear exchange on or above their home soil would 
46

have devastating consequences for their civilian populations. Given this 

context – which applied to parties on both sides of the superpower divide 

– many allied strategists believed relatively small nuclear arsenals were 

sufficient for the purposes of stable nuclear deterrence. 

Most U.S. allies thus supported the United States and Soviet 

Union negotiating an agreement establishing a ceiling for their strategic 

nuclear arsenals, convinced this form of superpower nuclear parity could 

provide sufficient weapons for their protection and prevent a spiraling 

arms competition that threatened to destabilize relations between 

Washington and Moscow.105 As a result, NATO allies backed the Nixon 

administration’s decision to initiate the Strategic Arms Limitation Talks 

(SALT) with the Soviet Union in November 1969, recognizing that the 

limits on strategic nuclear forces sought at the negotiating table would 

not affect the U.S. provision of extended deterrence to the alliance. 

Importantly, however, states such as the United Kingdom worked hard to 

coordinate allied efforts to keep non-strategic systems such as DCA, 

which they viewed as critical to NATO’s defense, out of the 

negotiations.106 As NATO noted in a December 1970 communiqué titled 

“Alliance Defence for the Seventies,” the alliance “hoped that success in 

strategic arms limitation talks will be achieved” but also reaffirmed that 

“Allied strategic nuclear capability will in any event remain a key 

element in the security of the West during the 1970s.”107 

Throughout the SALT process, a number of key NATO allies 

stressed that ongoing consultations on the progress of negotiations were 

important to their assurance. The Nixon administration agreed to do so, 

and in 1971 members of the alliance noted their “satisfaction ... for the 

close Alliance consultation which has been conducted throughout the 

course of the Strategic Arms Limitations talks” and also “expressed the 

hope that these negotiations will soon lead to agreements which would 

curb the competition in strategic arms and strengthen international peace 

and security.”108 With many U.S. allies remaining deeply skeptical of the 

strategic value of missile defenses, the successful negotiation through 

SALT of the 1972 Anti-ballistic Missile Treaty was favorably received 

by most allied governments, who did not believe the accord’s limits on 

missile defense systems would impact the ability of the United States to 

fulfill its mutual defense obligations.109

From Countervalue to Counterforce Strategies. The concepts of 

flexible response and assured destruction continued to shape U.S. nuclear 

strategies and the development and posturing of forces into the 1970s. 

For the purposes of deterrence, extended deterrence, and allied 

assurance, these concepts remained important to Washington’s efforts to 
47

protect the United States and its allies from the Soviet Bloc’s nuclear and 

conventional arsenals. During the Kennedy administration, the United 

States had retained significant qualitative and quantitative advantages in 

nuclear forces. By the 1970s, however, the Kremlin fielded both nuclear 

and conventional forces larger than the capabilities fielded by the United 

States and its allies.

Working within the general constructs of these two overarching 

concepts, U.S. strategists continued to develop plans that could use 

escalating levels of conventional or nuclear forces to respond to Soviet 

provocations without triggering Armageddon. This balancing act was 

reflected in documents such as NATO’s Military Committee document 

14/3, published in January 1968. The guidance document stated that the 

alliance “must be manifestly prepared at all times to escalate the conflict, 

using nuclear weapons if necessary” in response to a potential attack by 

the Warsaw Pact. It also noted, however, that 

[t]he effects of nuclear war would be so grave that the 

Alliance should engage in such action only after the 

possibilities of preserving or restoring the integrity of the 

NATO area through political, economic and 

conventional options had been tried and found 

insufficient.110

Document 14/3 also maintained the alliance’s strategy of calculated 

ambiguity in regard to possible nuclear weapons use, which member 

states agreed remained critical to leaving the Warsaw Pact in doubt 

regarding what type of aggression might lead to a nuclear response. As 

noted by the NATO commander responsible for the defense of its 

vulnerable central front,

We had one great advantage ... Despite all its 

knowledge of NATO, the Soviet General Staff could 

never be certain of the exact circumstances in which we 

would ‘go nuclear’ [for the simple reason that the 

members of NATO themselves did not know]

111

The United States continued its efforts to assure its allies that it 

possessed a broad range of military forces and attack options (both 

conventional and nuclear) to remain fully in control of a clash with the 

Soviet Bloc, to include nuclear strikes of limited scope (such as 

battlefield use against Soviet tank columns). Until the early 1970s, 

however, U.S. delivery systems lacked the technological sophistication 

required to fully realize these strategies or accompanying plans. 

Amongst other requirements, limited or flexible nuclear options required 

delivery systems and warheads that could maintain a very high degree of 
48

reliability and accuracy in even the most hostile operating environments. 

In the absence of these systems, the U.S. military found it needed to 

develop plans featuring significant numbers of nuclear forces to 

guarantee the destruction of even a relatively small set of target 

objectives. It also found it difficult to effectively limit the effects of a 

nuclear strike. 

This posed a major problem to efforts to develop either “limited” 

or “flexible” strike options. For several years “flexible response” 

represented a U.S. deterrence/extended deterrence concept that was 

important in theory but difficult to implement in practice. As a result, it 

was not until the mid-1970s that specific niche categories of targets came 

into U.S. war plans, first appearing within the 1974 Nuclear Weapons 

Employment Policy as part of the Schlesinger Doctrine (named for 

Richard Nixon’s Secretary of Defense, James Schlesinger). As 

Schlesinger testified to Congress, the United States needed

[o]ptions which did not imply immediate escalation to 

major nuclear war... What we need is a series of 

measured responses to aggression which bear some 

relation to the provocation, have some prospect of 

terminating hostilities before general nuclear war breaks 

out, and leave some possibility for restoring 

deterrence.”112

Innovations in military technology coming to fruition during the Nixon 

and Gerald Ford administrations finally allowed the United States to 

develop nuclear delivery systems and weapons capable of carrying out 

deterrence by denial strategies that only targeted Soviet nuclear forces. 

The central document marking this shift from countervalue to 

counterforce deterrence strategies, NSDM-242, emphasized the goal of 

early war termination on grounds acceptable to the United States, with 

limited nuclear employment options a key approach to fighting any 

conflict. At the same time as nuclear forces were becoming more 

accurate, better intelligence gathering assets were also becoming 

available, thus granting the United States additional tools to better 

identify targets and minimize collateral damage.113

While the United States retained significant deterrence by 

punishment options, by the mid-1970s deterrence by denial strategies 

were receiving greater emphasis in U.S. guidance documents. 

Improvements in military technology granted the United States the 

ability to develop strategies and plans that better reflected the doctrine in 

documents such as NATO 14/3. Increased accuracy, precision, and the 

ability to limit damage were associated with increased credibility; in 

theory, the president would not be “self-deterred” by fears that the only 
49

available options would cause large numbers of adversary casualties and 

might trigger a massive nuclear exchange destroying both superpowers. 

U.S. leaders and strategists hoped that in the eyes of both adversaries and 

allies the significant qualitative improvements to U.S. nuclear forces 

realized during the 1970s demonstrated the United States possessed both 

the political resolve and military capability to effectively respond to 

potential threats and attacks against its friends around the globe.

The SS-20 Crisis. Soviet leaders recognized the United States 

faced a number of challenges in extending a nuclear umbrella over the 

European members of NATO. In the mid-1970s, they began deploying 

the SS-20 intermediate-range ballistic missile (IRBM) in its western 

regions, hoping the threat posed by the new weapon system would strain 

and fracture the alliance.114 The SS-20 was a mobile missile that upon 

initial deployment could lay a credible claim to representing the most 

sophisticated and highly capable nuclear delivery systems in Europe.115 

It could not, however, reach U.S. territory, nor did it change the overall 

balance of nuclear forces between the two superpowers, both of which 

possessed hundreds of longer-range “strategic” delivery systems and 

thousands of warheads. 

As such, the SS-20 was clearly designed for the European theater 

and intended for NATO targets on the continent. The Soviet IRBM thus 

posed a direct challenge to U.S. assurance strategies for the alliance. A 

failure to adequately respond to the threat would leave NATO allies 

wondering if the United States was prepared to challenge the Soviet 

Union over a weapon system that did not pose a direct threat to the U.S. 

homeland. A 1978 briefing to the Secretary of State on the SS-20 and 

other recent improvements to Soviet nuclear forces summarized the 

assurance problem facing Washington: the deployment of the IRBM had 

“reawakened Allied concerns about the credibility of NATO’s posture 

and the US commitment [to their defense].”116

As a result, the SS-20 precipitated a slow-burning crisis for the

Jimmy Carter administration that continued into Ronald Reagan’s

presidency. U.S. allies pressed the United States for a direct response to 

the SS-20. At the same time, however, they were also wary of hosting 

additional U.S. nuclear forces on their own soil. Several faced 

determined internal political opposition and vocal protest movements 

demanding they either block the placement of additional nuclear forces 

on their home territory or calling for the removal of all U.S. nuclear 

weapons from Europe. In addition, many NATO states also continued to 

strongly support further superpower arms control talks, and asked that 
50

the alliance’s response to the SS-20 not jeopardize further bilateral 

diplomacy on nuclear weapons issues between Washington and Moscow. 

These factors led the United States and NATO to adopt a “dual 

track” approach in response to the challenge posed by the SS-20. In 

keeping with the Harmel Report, the alliance would combine efforts to 

boost its nuclear deterrent by adding U.S. intermediate-range nuclear 

forces to counter the Soviet IRBM while simultaneously communicating 

a willingness to start a new round of superpower nuclear arms control 

negotiations focused on this class of weapons. The first track would 

focus on developing nuclear forces capable of acting as a direct 

counterweight to the SS-20, with the United States deploying groundlaunched cruise missiles (GLCMs) and Pershing II IRBMs to its bases in 

Western Europe. At the same time, the United States would pursue a 

second diplomatic track focused on bringing the Soviet Union to the 

negotiating table in order to discuss a treaty eliminating IRBMs and 

other nuclear-delivery systems that posed a threat to each side’s allies in 

Europe.117

The strategy sought to restore the credibility of U.S. nuclear 

commitments to NATO while also addressing calls from European allies 

for additional nuclear arms control. It continued the trend, dating to the 

Harmel report, of committing the alliance to both maintaining a strong 

(nuclear) deterrent and supporting initiatives promoting détente between 

the superpowers and their respective blocs. Despite facing a number of 

serious challenges – to include major political protests in NATO states 

against the deployment of the new U.S. systems, and a serious 

breakdown in U.S.-Soviet arms control talks in November 1983 – the 

strategy ultimately proved successful on both tracks. The deployment of 

U.S. nuclear-delivery systems matching the SS-20 reassured NATO 

allies of the U.S. commitment to protect them from Warsaw Pact nuclear 

provocations or attacks. Further reassurance was provided by the U.S. 

willingness to initiate nuclear arms control talks with the Kremlin and 

place systems such as the Pershing on the table in exchange for the SS20. The diplomatic track also bore fruit. U.S.-Soviet arms control 

negotiations focused on IRBMs and related systems led to the successful 

negotiation of the 1987 Intermediate- and Shorter-Range Nuclear 

Missiles Treaty (INF), which eliminated all U.S. and Soviet missiles with 

ranges of 500-5500 km.

Rejecting “Star Wars” and Re-Affirming Nuclear Extended 

Deterrence. President Reagan came to office determined to improve the 

U.S. military’s conventional and nuclear forces in order to respond to 

quantitative and qualitative improvements in Soviet military hardware. 
51

His administration also continued the trend of shifting U.S. nuclear 

strategy to emphasize counterforce and deterrence by denial approaches. 

A significant increase in U.S. defense spending led to considerable 

progress in developing the capabilities necessary to actually implement 

such a strategy, to include new weapons and intelligence, surveillance, 

and reconnaissance (ISR) systems. As with a number of his 

predecessors, however, Reagan was dissatisfied with the options 

available to him in the event of a nuclear crisis or conflict. This led to an 

interest – first publicly expressed in 1983 – in seeking means to shield 

the United States and its allies from Soviet ballistic missile strikes with a 

true national missile defense system.

Allied political and military leaders were divided over Reagan’s 

efforts in his first term to bolster U.S. conventional and nuclear forces. 

Some welcomed U.S. efforts to respond to recent Soviet arms build-ups, 

but others preached caution, fearing that U.S. and Soviet leaders were 

each taking steps that were inadvertently ratcheting up tensions between 

the superpowers.118 U.S. allies during the early 1980s recognized the 

Soviet Bloc continued to pose a formidable military threat to their 

security. They also worried, however, that the United States and Soviet 

Union were endangering the limited – but in their view, critically 

important – progress on nuclear arms control that had led to agreements 

such as the 1972 ABM and SALT I Treaties. 

As a result, most reacted negatively to President Reagan’s March 

23, 1983 speech announcing his intent to investigate a high-technology 

solution to the existential threat posed by nuclear-armed ballistic 

missiles. In his speech the president stated that the challenges of the 

nuclear age had led him to ask:

What if free people could live secure in the knowledge 

that their security did not rest upon the threat of instant 

U.S. retaliation to deter a Soviet attack, that we could 

intercept and destroy strategic ballistic missiles before 

they reached our own soil or that of our allies?119

Reagan hoped the answer to these questions could be provided by 

researching and ultimately developing a cutting-edge, effective missile 

defense system capable of fully protecting the United States and its allies 

from the Soviet ballistic missile fleet. He also believed effective 

defenses could significantly reduce both sides’ dependence on nuclear 

deterrence and precipitate serious discussions on major superpower arms 

reductions.120 This effort – officially titled the Strategic Defense 

Initiative (SDI), but soon dubbed “Star Wars,” due to the possibility a 

future U.S. missile defense system might include components deployed 

in space – met with broad skepticism, and in some cases strong 
52

opposition, in most allied capitals. U.S. allies shared Reagan’s interest in 

finding a way to eliminate the threat posed by Soviet nuclear forces, but 

many viewed the missile defense shield proposed by SDI as an expensive 

gamble that threatened the ABM Treaty and other limited gains realized 

during the SALT talks of the late 1960s and 1970s and the ongoing INF 

talks. They also feared SDI would destabilize the nuclear deterrence 

relationship between the superpowers and their respective blocs, perhaps 

leading the Soviet Union to further increase its nuclear arsenal or take 

other steps to offset U.S. efforts to develop an effective active defense 

system against its nuclear forces. As one contemporary commentator 

observed in discussing the trepidation of NATO’s European members 

regarding SDI, “[m]any Europeans instinctively regard the introduction 

of major new military technologies as either a threat to stability or as a 

futile attempt to provide hardware answers to political questions.”121

Some allies also worried that Reagan’s efforts to make nuclear 

weapons irrelevant to the superpower relationship might leave them 

outside of U.S. strategic planning and defenseless against the 

conventional superiority of the Warsaw Pact. If SDI worked and the 

United States decided to dismantle many of its nuclear weapons, what 

would prevent the Red Army and its allies from using its conventional 

superiority to steamroll over Western Europe? “Increased security for the 

territories of the Soviet Union and the United States,” argued Helmut 

Schmidt, German Chancellor from 1974-1982, “could only be added [at] 

the cost of reduced security in Europe.”122

U.S. allies responded to SDI by arguing they were better assured 

by a combination of U.S. conventional forces (particularly those 

deployed to overseas bases on their home territory), a robust U.S. nuclear 

deterrent (to include both strategic and “non-strategic” systems), and 

commitment from Washington to superpower diplomacy aimed at 

reducing tensions and limiting nuclear forces. Their objections to SDI 

also reiterated concerns expressed regarding previous U.S. missile 

defense proposals such as Safeguard. Twenty years later, they still 

believed the systems proposed were too uncertain, expensive, and risky 

to provide a reliable defense against nuclear attacks. Furthermore, in 

rejecting SDI they re-affirmed their commitment to the status quo of the 

U.S. nuclear umbrella guaranteeing their security against the 

conventional and nuclear threats of the Soviet bloc. 

This status quo remained largely in place for the remaining years 

of the Cold War. Neither SDI nor tentative discussions between U.S. 

and Soviet leaders on major nuclear reductions were realized during the 

1980s. While superpower arms control talks moved beyond the systems 

of the INF Treaty to consider limits on conventional and strategic nuclear 
53

forces, these discussions took place against the backdrop of significant 

numbers of U.S. conventional and nuclear forces (both tactical and 

strategic) remaining in place in Europe and East Asia – forces that 

continued to assure U.S. allies and serve as a deterrent to their 

prospective adversaries.

The 1991 Presidential Nuclear Initiatives. The dissolution of the 

Warsaw Pact in February 1991 removed a critical threat to NATO. Six 

months later, fearing the Soviet Union itself was falling apart, hardliners 

attempted a coup against President Mikhail Gorbachev. While the 

attempted takeover failed, U.S. officials became deeply concerned over 

the security of Soviet nuclear weapons, many of which were scattered 

over territory of the 15 Soviet republics preparing to declare their 

independence from Moscow. 

Hoping to encourage Moscow to consolidate its nuclear delivery 

systems and warheads, and convinced the nature of U.S. deterrence and 

extended deterrence strategies could change to reflect a reduced threat 

environment in Europe and East Asia, in September 1991 President 

George H. W. Bush announced a significant drawdown of U.S. tactical 

nuclear weapons deployed abroad and invited the Soviet Union to do the 

same. With the Soviet Union teetering on the brink of disintegration, he 

concluded that U.S. allies were no longer directly menaced by the threat 

of a major Soviet bloc invasion of Western Europe. Indeed, shortly after 

the Warsaw Pact disbanded, the European members of NATO pressed 

the United States to remove its ground-launched nuclear forces from 

their territory.123 

President Bush’s decision to fundamentally reduce the United 

States’ deployments and stockpiles of tactical nuclear weapons were later 

titled the “Presidential Nuclear Initiatives,” (PNIs). The president 

ordered the removal of the majority of the U.S. nuclear warheads

deployed in Europe and all of the nuclear warheads deployed to the 

Republic of Korea (ROK). The PNIs also removed all nuclear weapons 

from U.S. surface ships, attack submarines, and land-based naval aircraft, 

and cancelled several modernization plans for tactical nuclear weapons 

and delivery systems.124 Gorbachev responded by agreeing to a set of 

parallel Soviet PNIs, a pledge reiterated by his successor, Russian 

President Boris Yeltsin, in early 1992.

125

President Bush recognized the key role tactical nuclear weapons 

played in U.S. Cold War extended deterrence and assurance strategies, 

and sought to directly address potential allied concerns related to his 

decision to significantly reduce these forces. Prior to announcing the 

PNIs, he discussed his decision with a number of key U.S. allies, and 
54

took care to note within his speech that he received “valuable counsel 

from Prime Minister Major (UK), President Mitterrand (France), 

Chancellor Kohl (Germany), and other allied leaders.”126 President Bush 

also reassured U.S. allies that drawdowns in tactical nuclear forces did 

not imply either a weakening of the U.S. commitment to NATO nuclear 

sharing arrangements or a folding up of the U.S. nuclear umbrella that 

had long protected its European and Asian allies. He emphasized that 

the United States would “preserve an effective air-delivered nuclear 

capability in Europe” stating that these forces remained “essential to 

NATO's security.”127 In addition, in separate bilateral discussions with 

the United States’ East Asian allies, administration officials confirmed 

the PNIs would not affect the ability of the United States to deploy the 

submarine-launched Tomahawk Land Attack Missile-Nuclear (TLAMN), a weapon viewed by Japan and the ROK as important to U.S. nuclear 

guarantees in the Pacific.128 

The NATO allies welcomed the PNIs and the subsequent 

removal of over 90 percent of the U.S. tactical nuclear warheads 

deployed to Europe. At the same time, however, uncertainty regarding 

the future of the Soviet Union (and its successor, the Russian 

Federation), led the United States and NATO to remain committed to 

U.S. provision of extended deterrence to the alliance in the form of 

nuclear and conventional forces. The U.S. strategic nuclear arsenal, for 

example, continued to buttress the decreasing number of remaining 

tactical nuclear weapons deployed in Europe. In addition, significant 

numbers of U.S. conventional forces also remained in Europe. 

 This strategy was confirmed in NATO’s November 1991 “New 

Strategic Concept,” which stated that the Alliance 

agreed to move away, where appropriate, from the 

concept of forward defence towards a reduced forward 

presence, and to modify the principle of flexible 

response to reflect a reduced reliance on nuclear 

weapons 

while also reiterating that “[t]he presence of North American 

conventional and US nuclear forces in Europe remains vital to the 

security of Europe, which is inseparably linked to that of North 

America.”129 The experience of the recently-concluded Gulf War, where 

Iraqi dictator Saddam Hussein used ballistic missiles to threaten the 

cohesion of the U.S.-assembled coalition and attack U.S. and allied 

forces, also led the New Strategic Concept to endorse future efforts to 

develop missile defenses.130

The end of the Cold War thus brought about one significant 

change to U.S. extended deterrence and assurance strategies: the 
55

significant reduction of tactical nuclear weapons intended to protect 

allies from massed conventional forces in Central Europe and along the 

Korean DMZ. It also reaffirmed the enduring importance of the U.S. 

nuclear forces, (in the form of the strategic triad and a limited number of 

tactical weapons) and conventional forces deployed abroad, to these 

strategies. It also brought a subtle shift in allied views on missile 

defenses that became more important over time. Most U.S. allies had 

rejected efforts by Washington in the late 1960s and mid-1980s to 

introduce missile defenses into deliberations on defense strategy, 

viewing them as a potential threat to deterrence concepts that both 

shielded them from the Soviet Union and coupled their security with that 

of the United States. While many allies remained skeptical of national 

missile defense concepts into the post-Cold War era, Saddam Hussein’s 

use of Scuds in the 1991 Gulf War and the broader challenge of ballistic 

missile proliferation to other “third world” states led NATO to become 

interested in the potential role of theater missile defenses (TMD) in 

combined defense strategies. While allies remained uncertain and 

divided on the role of missile defenses in the years ahead, they 

increasingly became part of U.S.-allied discussions related to the 

development and implementation of extended deterrence and assurance 

strategies. 

Post-Cold War Deterrence, Extended Deterrence, and Allied 

Assurance

Lead but Hedge: The 1994 NPR. The Soviet Union came to an 

end in December 1991, and the new Russian Federation declared its 

intent to pursue peaceful relations with the United States and its allies. 

President William Clinton and his national security team came into office 

seeking to change the security dynamic between the two countries and 

hoping to realize a “peace dividend” by significantly drawing down the 

U.S. Cold War military. With the Russian Federation inheriting the 

formidable Soviet nuclear arsenal, however, the Clinton administration 

would also commit to maintaining a strong U.S. nuclear force and 

strengthen U.S. extended deterrence guarantees. 

These decisions stemmed from the administration’s completion 

in 1993-94 of the United States’ first Nuclear Posture Review (NPR), a 

comprehensive post-Cold War assessment of the nuclear strategies, 

posture, and forces of the United States. Subsequent administrations 

would follow this practice of ordering a detailed review of U.S. nuclear 

posture shortly after assuming office. The dominant theme of the 1994 

NPR was “lead but hedge.”131 The United States would “lead” with 
56

regard to seeking negotiations with the Russian Federation on numerical 

reductions in nuclear forces and spearheading cooperative efforts to 

secure the weapons, materials, and expertise associated with the Soviet 

nuclear arsenal.132 At the same time, however, it would maintain a 

significant nuclear arsenal to “hedge” against the possibility that 

Moscow might reverse its current trend of proactive diplomatic 

engagement. The review’s assessment of U.S. requirements for fulfilling 

deterrence, extended deterrence, and assurance missions found that the 

United States should continue to maintain a “roughly equivalent 

[nuclear] force” to the strategic nuclear deterrent fielded by the Russian 

Federation. Looking beyond Russia to other potential nuclear threats, the 

1994 NPR also argued in favor of maintaining a significant nuclear 

“hedge” due to concerns nuclear proliferation might result in the United 

States and its allies facing multiple nuclear-armed adversaries in the 

future:

133

The findings of the 1994 NPR led the Clinton administration to 

seek nuclear force reductions with Russia through the mechanism of 

arms control while also supporting the maintenance of a nuclear arsenal 

capable of deterring Russia and a range of other potential nuclear-armed 

adversaries. The administration’s 1994 National Security Strategy 

asserted that strategic nuclear forces remained critical to post-Cold War 

deterrence.

We will retain strategic nuclear forces sufficient to deter 

any future foreign leadership with access to strategic 

nuclear forces from acting against our vital interests and 

to convince it that seeking a nuclear advantage would be 

futile. Therefore we will continue to maintain nuclear 

forces of sufficient size and capability to hold at risk a 

broad range of assets valued by such political and 

military leaders.134

The Clinton administration also found the U.S. extended 

deterrence and assurance strategies continued to require both strategic 

and tactical nuclear weapons. Clinton administration officials 

considering the assurance needs of the NATO alliance, for example, 

strongly supported keeping U.S. tactical nuclear weapons in Europe. 

Appearing before Congress in September 1994, Deputy Secretary of 

Defense John M. Deutch stated that tactical nuclear weapons remained 

important to assuring NATO members and maintaining the credibility of 

the U.S. nuclear umbrella. While noting “the Russians no longer have 

the military capability to mount [a major] conventional attack” on 

Western Europe, Deutch emphasized that U.S. tactical nuclear weapons 
57

remained essential to U.S. assurance strategies for NATO via their 

central role in alliance nuclear-sharing arrangements:

The political purpose to maintain within the alliance 

shared responsibility for nuclear forces [remains 

important] and make[s] sure the Europeans know that 

they can rely in a serious way on our nuclear forces.135

In order to visibly confirm the continuing U.S. commitment to NATO’s 

security, the Clinton administration supported maintaining U.S. DCA 

and a limited number of tactical nuclear weapons in Europe. 

The Clinton administration also grappled with the question of 

whether nuclear weapons could still guarantee deterrence in a post-Cold 

War era. With dictators such as Kim Jong Il and Saddam Hussein 

demonstrating a willingness to take enormous risks in order to challenge 

the United States and threaten its allies, President Clinton wondered if in 

the future “a hostile state with nuclear weapons ... might miscalculate, 

believing it could use nuclear weapons to intimidate us from defending 

our vital interests, or from coming to the aid of our allies.”136 “Rogue 

states” such as North Korea and Iraq did not appear to abide by the 

deterrence calculations of the Cold War. As a result, the president and 

his national security team concluded that nuclear weapons represented a 

necessary, but not sufficient, means for deterring nuclear attacks against 

the United States and its allies. U.S. deterrence and extended deterrence 

strategies, even when backed by effective nuclear capabilities, might fail 

to prevent a dictator from launching ballistic missiles – to include 

missiles armed with WMD – against the United States, its forces 

deployed overseas, or its allies. 

As a result, the Clinton administration supported the continued 

development of regional missile defenses as a potential supplement to the 

deterrent value of U.S. nuclear and conventional forces.137 It recognized 

the growing importance of these systems to the assurance of allies such 

as Japan, which was increasingly concerned about the threat posed by 

North Korean missile programs.138 

The administration was less certain, however, regarding national 

missile defense concepts. It remained committed to the ABM Treaty and 

worried that a U.S. national missile defense (NMD) system would 

damage relations with Moscow. Allies echoed this concern, counseling 

the United States against any major “national” or “global” system; for 

many, these latter systems were not worth the price of upending U.S.-

Russian strategic stability.139 NATO states remained determined to 

maintain a clear demarcation between “strategic” and “theater” missile 

defenses.140 As the Clinton administration considered various missile 

defense options during its second term, for example, French President 
58

Jacques Chirac and German Chancellor Gerhard Schroeder separately 

issued public statements warning that any U.S. plans to consider a NMD 

system could lead to another U.S.-Russia nuclear arms race.141 

Ultimately the president elected to support the research and development,

but not deployment, of a limited national missile defense system 

designed to protect the United States from a the small ballistic missile 

arsenals of states such as Iran and North Korea.142 

The 1990s thus continued the gradual evolution of U.S. extended 

deterrence and assurance strategies. The collapse of the Soviet Union 

and dissolution of the Warsaw Pact removed an existential threat to the 

United States and its allies, and in its first term the Clinton 

administration cut defense spending and sought significant reductions in 

the numbers of U.S. military personnel stationed in Europe.143 U.S. 

strategists in the 1990s concluded that a mix of forces – conventional and 

nuclear, now joined by short- and medium-range missile defense systems 

– were required to assure U.S. allies and deter their adversaries. 

These views were shared by most U.S. allies. NATO’s 1999 

Strategic Concept, for example, stated its support for additional arms 

control agreements leading to further reductions in U.S. and Russian 

nuclear forces. It also noted, however, that the continued existence of 

“powerful nuclear weapons outside the alliance” posed an enduring 

threat requiring NATO to continue its reliance on nuclear deterrence:

[the] Alliance's conventional forces alone cannot ensure 

credible deterrence. Nuclear weapons make a unique 

contribution in rendering the risks of aggression against 

the Alliance incalculable and unacceptable. Thus, they 

remain essential to preserve peace.144

In addition, the document reiterated the alliance’s longstanding view that 

“the presence of United States conventional and nuclear forces in Europe 

remains vital to the security in Europe.” It also stated that the alliance 

would continue “work on missile defenses” to address the growing 

challenge of WMD and missile proliferation.145

Conventional, nuclear, and missile defense forces were also 

important to U.S. extended deterrence and assurance strategies in East 

Asia, Although differing assessments regarding the utility of the latter 

precluded development of a region-wide missile defense concept, 

cooperation on testing system components and developing platforms 

became important to defense relationships with key allies. The United 

States and Australia’s Project DUNDEE, for example, tested 

sophisticated boost-phase detection systems in 1997 as part of broader 

cooperation on research and development of radar and sensor capabilities 

related to TMD, activities Canberra considered important to “bolstering 
59

the [U.S.-Australia] alliance.”146 In addition, the DPRK’s continued 

development of ballistic missiles and WMD led the United States and 

Japan in 1999 to agree to add missile defenses – in the form of combined 

efforts to develop a naval-based TMD – to the 55,000 U.S. military 

forces posted in country, and offshore U.S. nuclear forces providing a 

nuclear umbrella, as a key component of U.S. defense guarantees to this 

key ally.147

While the end of the Cold War had significantly improved the 

prospects for U.S. and allied security, at the close of the 20th century U.S. 

and allied policymakers and strategists continued to view both U.S. 

nuclear forces and conventional “boots on the ground” as important to 

extended deterrence and assurance missions. Moreover, new threats that 

came to the fore during the 1990s in the form of “rogue states” pursuing 

WMD and their means of delivery appeared to underline the importance 

of maintaining both a robust nuclear deterrent and investigating the 

possible use of missile defenses to provide protection against the limited, 

but nonetheless potentially lethal, missile arsenals of countries such as 

North Korea. 

Re-thinking Deterrence Requirements: 9/11 and the “New 

Triad.” The administration of President George W. Bush came to office 

interested in working with the Russian Federation to significantly reduce 

each side’s nuclear arsenals. It was also determined to press forward 

with the deployment of a national missile defense system, a decision that 

ultimately led the United States to withdraw from the ABM Treaty in 

2002. The Bush administration’s national security team believed U.S. 

views on nuclear forces, missile defenses, and arms control remained 

saddled with concepts developed during the long confrontation between 

the United States and Soviet Union. They were determined to reexamine and, if necessary, re-tool U.S. strategies and forces associated 

with deterrence, extended deterrence, and assurance strategies in order to 

better address the complex threats faced by the United States and its 

allies in the 21stcentury geopolitical environment.

The September 11, 2001 terrorist attacks had a profound impact 

on the Bush administration’s world view and assessment of national 

security imperatives. In regard to its views on deterrence, however, the 

attacks confirmed a number of key conclusions within the 

administration’s 2001 NPR which commenced shortly after the 

administration entered office and was largely complete prior to 9/11. 

The authors of the review were guided by President Bush’s conviction, 

articulated in a May 1, 2001 speech at the National Defense University, 

that “[d]eterrence can no longer be based solely on the threat of nuclear 
60

retaliation.”148 Viewing the spectrum of potential nuclear threats faced 

by the United States, the 2001 NPR questioned the utility of continuing 

to rely on large numbers of strategic offensive nuclear forces to deter 

potential WMD attacks. U.S. deterrence concepts, it argued, needed to 

better integrate missile defenses and advanced conventional systems into 

strategies and operations addressing these challenges. It also rejected the 

idea that U.S. deterrence efforts should focus on the nuclear forces of 

Russia, expressly stating that the concept of mutually assured destruction 

was no longer applicable to the U.S.-Russia relationship. 149 The 2001 

NPR further argued that U.S. strategists needed to fundamentally rethink 

deterrence in a geopolitical environment where the United States and its 

allies were menaced by state and non-state actors whose cost-benefit 

calculations were unlikely to mirror those of the former Soviet Union, 

concluding “the United States can no longer take comfort in the Cold 

War belief that opponents will be deterred reliably and in predictable 

ways.”150 

In response to these challenges, the 2001 NPR suggested the 

United States needed to exchange its concept of a Cold War triad of 

strategic offensive nuclear forces (in the form of SLBMs, ICBMs, and 

bombers) for a “New Triad” of offensive systems (nuclear and 

conventional), defensive systems (nuclear and conventional, including

both active and passive defenses), and a “revitalized defense 

infrastructure.”151 It also found that most of the nuclear warheads within 

the U.S. arsenal, originally designed for missions such as attacks on 

Soviet ICBM silos, were irrelevant to deterring or attacking present 

security threats The review proposed pursuing new advanced 

conventional military options to reduce U.S. dependence on offensive 

nuclear forces, but also suggested the United States might need to 

“modify, upgrade or replace portions of the extant nuclear force or 

develop concepts for follow-on nuclear weapons systems better suited to 

the nation’s needs.”152 The latter finding led the administration to 

consider possibly replacing or re-designing some of the warheads within 

the U.S. nuclear arsenal.153 

In addition, the 2001 NPR also argued that a network of active 

and passive defenses significantly boost the ability of the United States 

to deter state or non-state adversaries, stating that “by denying or 

reducing the effectiveness of limited attacks, defenses discourage 

attacks.”154 The development of an active deterrence by denial capability 

– in this case, denying an adversary from realizing any benefits from a 

ballistic missile attack – was considered particularly important because 

some contemporary adversaries might not fear the threat of deterrence by 

punishment, whether due to ideological fanaticism, a callous disregard 
61

for the safety of their own populations, or both. The review concluded 

that bringing together offensive and defensive systems would 

significantly improve the prospects for deterring a range of adversaries –

to include “terrorists or rogue states armed with weapons of mass 

destruction” – by providing the United States with the means to employ 

both deterrence by denial and deterrence by punishment strategies.155 

The 2001 NPR also adopted the perspective that U.S. extended 

deterrence and assurance concepts needed to shift away from past Cold 

War frameworks. The “New Triad,” it asserted, would provide the 

United States with offensive and defensive capabilities “credible to 

enemies [and] reassuring to allies.”156 The 2001 NPR stated that 

maintaining a “second to none” U.S. nuclear deterrent – quantitatively 

lower, but perhaps qualitatively improved from the Cold War arsenal –

“assures allies”157 The review also found, however, that U.S. extended 

deterrence and assurance strategies were far too dependent on nuclear 

forces. During a briefing to the media on the results of the 2001 NPR, 

Assistant Secretary of Defense for International Security Policy J.D. 

Crouch explained that in order to meet the contemporary requirements of 

allied assurance, “we believe that developing credible non-nuclear and 

nuclear response options [are] necessary to supporting U.S. 

commitments.”158 

In regard to defensive systems, for example, the 2001 NPR 

concluded that continuing to improve and expand U.S. missile defense 

systems would assure allies by allowing the United States to deploy 

capabilities overseas capable of shielding their home territories from 

missile attacks.159 In addition, missile defense would also enhance U.S. 

assurance strategies by allowing the United States to better protect forces 

deployed abroad for the purposes of allied defense.160 Furthermore, the 

deployment of effective national and regional missile defenses might 

convince adversaries to give up continued investments in missiles 

intended to threaten the United States and its allies.161 The review was 

willing to take U.S. missile defense further than the Clinton 

administration, expressly stating that it would develop systems “more 

capable than the ABM Treaty permits” in order to develop defenses able 

to address the increasingly numerous and sophisticated ballistic missiles 

fielded by U.S. and allied adversaries.162

Many U.S. allies, however, did not agree with the conclusions 

reached by the 2001 NPR on offensive or defensive systems. Criticism 

was generally muted in the immediate aftermath of the 9/11 attacks, but 

over time a number of allied governments became increasingly uneasy 

with U.S. policies and strategies derived from, or supported by, the 

results of the review.163 They feared the broad spectrum of new military 
62

capabilities called for by the 2001 NPR could damage relations between 

the United States and other nuclear powers such as Russia and China, 

and threaten to blur the distinction between conventional and nuclear 

war. In addition they and were not the best means for confronting 

contemporary threats. Underlining these objections was a broader 

concern that President Bush and his advisors were uninterested in allied 

views on issues of national security and dismissive of international laws 

and institutions that many allies considered vital to global stability. 

These concerns came to a head over serious disagreements between the 

United States and several key allies regarding the U.S. decision to invade 

Iraq in 2003. In the aftermath of “Operation Iraqi Freedom” some U.S. 

allies feared the Bush administration was determined to undertake a 

range of unilateral actions that would destabilize global affairs and 

ultimately complicate their own efforts to grapple with the challenges of 

the post-9/11 security environment.164

Plans to develop a NATO missile defense system against 

possible future ballistic missile threats from countries such as Iran, for 

example, became a major point of contention within the alliance during 

the Bush administration’s two terms in office. While states such as 

Poland and the Czech Republic welcomed the opportunity to host 

components of the system, other members of the alliance feared Russia’s 

strong objections to the plans would prompt Moscow to respond with 

actions detrimental to their national security. Some NATO members 

also questioned what they viewed as the Bush administration’s overreliance on missile defenses to counter security threats, arguing that 

potential adversaries faced with these defenses would simply develop 

means other than ballistic missiles to attack the alliance.165 In the interest 

of reaching consensus, the alliance ultimately agreed in April 2008 to 

“develop options for a comprehensive missile defense architecture” for 

protecting the entire alliance, but did not endorse a particular strategy or 

system.166

President Bush’s national security team hoped to close the door 

on the deterrence concepts of the Cold War and replace them with new 

strategies for defending the United States and its allies. The 2001 NPR 

argued that U.S. deterrence strategies, and the forces assigned to carry 

them out, were designed and developed to counter an adversary that no

longer existed. However, its suggestions for re-thinking deterrence, 

extended deterrence, and assurance concepts, and for overhauling and/or 

expanding the military tools associated with these concepts, failed to 

gain traction with many U.S. allies. Many allied objections to the ideas 

of the 2001 NPR stemmed from concerns regarding the Bush 

administration’s general approach to international affairs rather than 
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specific objections over threat assessments or military strategy. But 

allies also proved skeptical of the 2001 NPR’s conclusions regarding 

missile defenses and nuclear weapons. For many, the review appeared 

too confident of the ability of new offensive and defensive military 

capabilities to negate a broad range of threats from state and non-state 

actors. Allies also feared the review either overlooked or ignored the 

likelihood that non-allied major powers might respond negatively to 

major changes in U.S. deterrence strategies. A number of NATO allies 

were also dismayed by the Bush administration’s express rejection of 

earlier U.S. approaches to nuclear arms control, viewing the ABM Treaty 

and other previous U.S.-Russia accords as important to stabilizing a 

relationship that remained critical to alliance security. 

As a result, the 2001 NPR had a limited impact on U.S. extended 

deterrence and assurance strategies. Its attempt to lift the profile of 

missile defenses within these strategies reflected their increasing 

importance in a post-Cold War era marked by the continuing 

proliferation of nuclear weapons and ballistic missile technology. Efforts 

to implement these plans, however, met with mixed success. In addition, 

while the United States reduced its number of operationally deployed 

nuclear warheads due to the Bush administration’s successful negotiation 

of the 2002 Strategic Offensive Reductions Treaty (SORT) with Russia, 

the importance of nuclear weapons within U.S. extended deterrence and 

allied assurance strategies remained largely unchanged. For its part, the 

Russian Federation rejected U.S. overtures to consider fundamentally 

changing the nuclear deterrence relationship between the two states, 

insisting this form of deterrence remained essential to maintaining U.S.-

Russia strategic stability.167 Allies also proved reluctant to jettison 

deterrence concepts and strategies that had long provided for their 

security. NATO’s 2006 “Comprehensive Political Guidance,” for 

example, noted that even in an era of “asymmetric” threats “[t]here will 

continue to be a requirement for a mix of conventional and nuclear 

forces,” a mix that remained heavily reliant on the capabilities provided 

by the U.S. military presence in Europe.168 The guidance document also 

noted the need to protect the alliance against ballistic missile threats; 

significantly, however, it placed missile defenses within the context of 

“the ability to defend deployed NATO forces against theatre missile 

threats.”169 In response to Bush administration proposals to consider 

significant changes to the strategies and tools of extended deterrence and 

allied assurance, the general response of U.S. allies was to defend the 

status quo or press for limited adjustments to existing approaches.
64

Extended Deterrence and Allied Assurance: From the Cold War to 

the “War on Terror”

The four general challenges discussed above have proven 

independent of a specific adversary threat. Following the end of the 

Cold War, for example, the United States and its allies continued to face 

a range of nuclear and conventional threats. Most of the United States’ 

Cold War allies remained reliant on the United States to guarantee or 

significantly shore up their defense of their home territories and core 

national interests. Within this context the U.S. policy imperative to 

protect allies in Europe, East Asia, and elsewhere has remained in effect. 

So too has the requirement to use many of the tools within the U.S. 

military’s toolbox to provide for their defense, to include conventional, 

nuclear, and, in the post-Cold War era, missile defenses. Improved tools, 

however, granted the ability to change strategies away from an early 

reliance on deterrence by punishment in the form of massive nuclear 

strikes to more limited nuclear and conventional strike options. Into the 

post-Cold War era, deterrence by punishment approaches were also 

increasingly joined by plans, options, and assets for deterrence by denial 

strategies seeking to focus the striking power of the U.S. military on key 

adversary pressure points while limiting the effects of war on the civilian 

populations of adversary states. 

At the close of the George W. Bush administration, U.S. 

extended deterrence and allied assurance strategies – while significantly 

evolved from those employed during the early Cold War period, and 

strained in some cases by disagreements between Washington and allied 

capitals during and after the Second Gulf War – remained central to the 

defense policies and planning of the United States and many of its key 

allies. Sixty years after the Allies’ victory over the Axis powers, and 

nearly twenty years after the collapse of the Soviet bloc, the United 

States continued to represent the primary security broker for states across 

the globe, with significant conventional forces deployed abroad, strategic 

nuclear forces on rotation or patrol in key regions, and tactical nuclear 

weapons remaining available for the defense of NATO or East Asia 

against nuclear threats. We will examine current U.S. policies in greater 

detail in Part 5. 
65

PART 4: CONTINUITY AND CHANGE IN U.S. EXTENDED 

DETERRENCE AND ASSURANCE POLICIES, STRATEGIES, AND 

FORCES (1945-2008)

Policies

From the end of the Second World War through the early 21st

century, the United States and its allies weathered dramatic changes in 

geopolitics, threats from a range of adversaries, and the vagaries of intraalliance policy and strategy debates. Across this period of time, 

however, the policies of the United States driving the requirements of 

deterrence, extended deterrence, and assurance strategies remained 

constant in three important ways. 

First, the United States assumed a mantle of geopolitical and 

geostrategic leadership for states facing threats from ideological 

totalitarian, anti-democratic regimes. This rogue’s gallery of potential 

adversaries changed over time, but the threat – whether in the form of the 

Soviet Union and its proxies during the Cold War, or states such as the 

DPRK and Iran in the post-Cold War era – posed by these regimes to the 

United States and its friends abroad has led several generations of 

decision-makers in Washington to firmly back efforts to establish and 

maintain a common defense perimeter in order to protect its allies and 

deter their enemies. 

Second, the United States committed itself to a defense posture 

that includes forces permanently or regularly deployed abroad in order to 

implement its extended deterrence and assurance strategies. For over 60

years the United States has deployed military forces – often accompanied 

by their dependents – at permanent bases in Europe and East Asia while 

also maintaining semi-permanent facilities and regular force rotations in 

other regions. The purpose was to demonstrate America’s willingness to 

risk blood and treasure on behalf of an ally’s defense. These U.S. forces 

provide a direct form of assurance to the host state and regional allies. 

Their presence can also deter potential adversaries due to their inherent 

capabilities and the visible proof they offer of the U.S. determination to 

honor its defense commitments. 

Third, the United States has pledged to defend its allies from 

conventional and WMD threats, up to and including the threat of nuclear 

war. To meet these challenges, U.S. extended deterrence and assurance 

guarantees have traditionally relied upon a robust mix of both 

conventional and nuclear forces, to include conventional and tactical 

nuclear forces permanently deployed abroad. 
66

These policies have committed the United States to defending 

allies across the globe and deterring their potential adversaries using a 

broad range of military capabilities, to include significant numbers of 

forces stationed at permanent posts abroad. The United States continues 

to pledge itself to the common defense of states around the world;

remaining convinced an attack upon a friend by an ideologue, dictator, or 

terrorist would essentially represent an attack upon itself. Significantly, 

neither time nor geopolitical change has fundamentally altered the 

security guarantees offered by the United States to NATO and other

countries such as Japan, the ROK, and others. The United States’ 

enduring commitment to taking a lead role in promoting international 

stability and rallying like-minded allies against anti-democratic threats 

has led it to view extended deterrence and allied assurance as missions 

that are both global in scope and critical to its own national security. 

Strategies

Cold War

These policy imperatives continually shaped the development of 

U.S. extended deterrence and allied assurance strategies from 1945-2008. 

For much of this time period, the significant challenges associated with 

defending globally dispersed allies against a nuclear-armed superpower 

and its proxies led the United States to view nuclear forces as central to 

these strategies.

The roles and responsibilities of nuclear forces within extended 

deterrence and allied assurance strategies, however, evolved over time. 

Early Cold War U.S. deterrence concepts relied upon the ability of the 

United States to deliver an aerial attack destroying a large number of 

Soviet cities. This deterrence by punishment approach reflected the 

relative limitations of 1940s and 1950s U.S. delivery systems and 

warheads. It was also rooted, however, in a strategic assessment that 

only the threat of total destruction could hold the massive conventional 

armies fielded by the Soviet Bloc in check and ensure the protection of 

the United States and its allies. During the 1948-49 Soviet blockade of 

Berlin, for example, the United States Air Force developed a nuclear 

plan (“Fleetwood”) featuring a massive bombing strike against 70 Soviet 

cities using 133 nuclear gravity bombs.170

In time improvements to the range, accuracy, survivability, and 

flexibility of U.S. nuclear forces allowed U.S. strategists to increasingly 

focus war plans on adversary nuclear forces and other key military 

targets. Greater fidelity in nuclear strike options allowed consideration 

of focused attacks on one region or one type of target set. Deterrence by 
67

punishment strategies gradually gave way to a broader range of plans 

that included options for deterring the Soviet Union by threatening the 

destruction of its nuclear ICBMs, SLBMs, and bombers, and the forces 

and industries that supported its military machine. The intent was to 

disarm the Soviet Union with a relatively limited number of precision 

weapons rather than destroy it with a massive first strike. 

The requirements of defending allies led to the development of 

extended deterrence strategies that combined these long-range “strategic” 

forces with “tactical” forces deployed abroad to counter the superior 

conventional forces of the Soviet Union and its proxies. These latter 

type of forces were intended to leave Moscow in doubt regarding the 

level of provocation against countries aligned with the United States that 

could touch off a nuclear response from a U.S. fighter-bomber, shortrange missile, or artillery piece. They were also designed, postured, and 

exercised in a manner intended to maintain control over an escalating 

crisis and keep the potential use of nuclear weapons, if deemed 

absolutely necessary to prevent a catastrophic defeat, limited to the 

battlefield. 

These were strategic approaches predicated on the need to 

protect the “free world” from Soviet aggression while also preventing 

any conflict from spiraling out of control and precipitating a massive 

nuclear exchange leaving both superpower blocs destroyed. The 

development in the mid- to late Cold War period of flexible, limited 

nuclear options reduced the United States’ reliance on assured 

destruction as the primary means to deter attacks upon itself and its allies 

around the globe. A recent analysis by Elbridge Colby summarizes this 

evolution well:

During the Cold War the U.S. government, once it 

perceived that the Soviets would eventually achieve the 

assured ability to inflict unacceptable damage upon the 

U.S. homeland, came to believe that the United States 

needed to be able to employ its nuclear forces in a 

limited manner. Preparation for controlled use was 

necessary to be able to retain the benefits of nuclear 

weapons, whose use in an unrestrained fashion was 

taken to be of little credibility and therefore of limited 

utility. While administrations differed about how limited 

nuclear use would be conducted particularly beginning 

with the Nixon administration they did not differ on the 

basic premise that the United Sates did need to be able to 

employ nuclear weapons selectively. Nor was this effort 

merely confined to the declaratory level. Beginning with 
68

SIOP-63 [Single Integrated Operational Plan 63], 

accelerating with SIOP-5 in 1976, and coming to fruition 

with the late SIOP-6 series of 1986 and after, U.S. war 

plans included specific, concrete options for limited 

nuclear use.171

The shift from countervalue to counterforce strategies, and the search for 

“limited” nuclear options that could deter the Soviet bloc (and prevent 

the United States from deterring itself), represented significant changes 

to U.S. deterrence and extended deterrence concepts over the course of 

the Cold War.

Post-Cold War

However, these changes over time, while important, remained 

largely confined to offensive nuclear forces and plans involving nuclear 

strikes. For much of the Cold War, deterrence strategies focused on 

offensive forces. Cold War theorists devoted considerable attention to 

the theoretical ability of defenses to influence or perhaps even negate 

deterrence strategies reliant on nuclear forces. Ultimately, however, a 

combination of factors led most Cold War U.S. strategists to view 

offensive forces as better for the purposes of deterrence and, more 

broadly, as critical to establishing a stable strategic relationship between 

the superpowers. Effective national passive defenses against large-scale 

nuclear attacks came with a prohibitive price tag; for this and other 

reasons, they were politically unpopular, and only limited steps were 

taken in areas such as civil defense. Active defenses, in the form of 

ballistic missile defense systems, were expensive, remained 

quantitatively and qualitatively behind the offensive threat, and for much 

of the Cold War were viewed by many key U.S. decision-makers (and 

many U.S. allies) as more likely to increase the scope and intensity of the 

superpower arms race and further strain relations between Washington 

and Moscow. 

In the post-Cold War era, technological advances and the 

evolution of adversary threats led the United States to re-examine the 

potential role of active and passive defenses. In turn, this also led to a 

renewed interest in deterrence-by-denial strategies derived from boosting 

one or both types of defenses. The use of missile defenses to deny an 

adversary any benefits from launching a ballistic missile attack on the 

United States or an ally became more important in discussions of U.S. 

and allied defense strategy as states such as Iraq, Iran, and the DPRK 

continued to build up their ballistic missile arsenals through the 1990s, 

and as missile defense technologies continued to improve (how much –

in terms of battlefield effectiveness – remaining an important question 
69

and subject of fierce debate, particularly in regard to NMD). This led the 

Clinton administration, for example, to press forward with TMD systems 

and regional missile defense cooperation despite its objections to NMD. 

Passive defenses also became more important, particularly in regard to 

the diverse WMD threats facing U.S. forces deployed abroad in the postCold War era. Few strategists had taken seriously the idea that physical 

defenses – or personal defensive gear – could play a role in protecting 

military personnel and facilities against a major Soviet nuclear attack. 

But protection against the CBRN (chemical, biological, radiological, or 

nuclear) munitions of states such as Saddam Hussein’s Iraq was 

enormously important to U.S. allies and U.S. forces deployed on behalf 

of their defense in the 1990s and beyond. 

These developments led defensive means and deterrence-bydenial strategies to become increasingly important to U.S. extended 

deterrence and allied assurance efforts in the post-Cold War, representing 

an important trend observed from surveying U.S. attempts to defend 

allies across the globe from the late 1940s into the early 21st century. 

The end of the Cold War removed a direct, existential threat 

facing the United States and its allies, and raised the question of whether 

nuclear deterrence remained critical to U.S. and allied defense strategies. 

Will nuclear deterrence remain important to these strategies, or did the 

end of superpower competition and arms racing signal that the United 

States and its allies could find other ways to guarantee their security? 

Presidents George H.W. Bush, Clinton, and George W. Bush all 

carefully considered, and approved, quantitative reductions to the U.S. 

nuclear arsenal and pursued major nuclear arms control agreements with 

Russia. All sought to alter the role of nuclear forces in U.S. deterrence 

strategies, noting the United States and its allies no longer faced a 

conventional force imbalance necessitating a nuclear counterweight. 

President George W. Bush even sought (albeit without success) to 

convince Russia that nuclear deterrence no longer played any role within 

U.S.-Russia relations. 

All three, however, also concluded nuclear deterrence remained 

vital to the security of the United States and its allies given the continued 

presence of nuclear weapons in the arsenals of U.S. competitors and 

potential adversaries. Moreover, the ongoing challenge of nuclear 

proliferation – with the DPRK becoming a nuclear power, and Iraq, Iran, 

and other states pursuing nuclear weapon development programs –

clearly demonstrated that nuclear threats to the United States and its 

allies were not simply a byproduct of the Cold War competition between 

the superpowers. What were the implications of nuclear forces playing a 

less central, but nonetheless vital, role in deterrence, extended 
70

deterrence, and assurance strategies? The 2001 NPR wrestled with this 

question, ultimately seeking to bring forward other forces (such as 

missile defenses) while also sharpening and focusing the nuclear arsenal 

on contemporary threats. The review’s conclusions, however, 

encountered serious objections at home and abroad, signaling that while 

the U.S. strategic community – and its allies – believed nuclear forces 

should be less prominent in deterrence strategies, there was little 

agreement on how to realize these changes and what other military tools 

should take their place. 

Forces

For decades, U.S. extended deterrence and assurance strategies 

have relied upon a robust mix of conventional and nuclear forces. While 

the numbers and capabilities of these forces have changed with time, the 

decades-long requirement to defend U.S. allies scattered across the globe 

from a range of conventional and WMD threats has led U.S. 

policymakers and planners to conclude that both types of forces are 

required to defend allies abroad. The United States has found it 

necessary to maintain conventional and nuclear forces at permanent 

bases hosted by friendly foreign nations, capabilities backed by 

additional forces engaged in ongoing air or sea patrols, assigned to 

regular rotations abroad, or stationed in the United States but prepared 

for rapid deployment overseas. In the post-Cold War era, missile 

defenses began to join this mix, as missile and WMD proliferation and 

technical improvements (particularly in short-range and theater systems), 

gradually overcame some allied objections regarding costs and 

uncertainty regarding the impact of “national” missile defenses on 

strategic stability. 

Conventional forces

U.S. conventional forces have long played an important role in 

assuring U.S. allies and deterring their adversaries. The United States, 

for example, has maintained, with host nation support, military bases in 

Germany, Japan, the Republic of Korea and other countries for decades. 

U.S. “boots on the ground” have long demonstrated the willingness of 

the United States to risk blood and treasure on behalf of its allies. For 

states with U.S. bases on their territory, these conventional forces 

represent a vital form of assurance. Throughout the Cold War, despite 

the considerable conventional force advantages of the Warsaw Pact, 

political and military leaders in Germany (and other countries with 

permanent U.S. military bases on their soil) believed the Soviet Union 

was unlikely to launch an invasion against a country hosting U.S. GIs, 
71

due to the Kremlin’s fears that such an attack could trigger a costly 

superpower conflict. 

Nuclear Forces

U.S. nuclear forces have also represented a central feature of 

U.S. extended deterrence and allied assurance strategies from the late 

1940s to the present. From the dawn of the nuclear age, nuclear weapons 

represented – by several orders of magnitude – the most devastating 

capability within modern military arsenals. As such, wherever U.S. 

allies have faced an adversary armed with nuclear weapons, the United 

States has found it necessary to counter this threat with a promise to 

protect its friends with U.S. nuclear forces. For allies living under a 

nuclear shadow, the willingness of the United States to go to nuclear war 

on its behalf represents a critical litmus test of the alliance relationship. 

Nuclear forces have also played an important role in assuring the 

credibility of extended deterrence and assurance strategies in 

circumstances where deterrence by conventional forces alone is in doubt. 

Whenever the United States and its allies found themselves outnumbered 

during the Cold War, for example, U.S. nuclear forces have often 

plugged the gap. Into the post-Cold War era, nuclear forces remained 

prominent within extended deterrence and assurance strategies. While 

their numbers declined as a result of policy decisions, arms control 

agreements, and retirement of a number of aging systems, both U.S. and 

key foreign leaders found U.S. strategic and tactical nuclear forces – with 

the latter’s visibility and flexibility important to both NATO and East 

Asian allies – continued to meet critical policy and strategy requirements 

in a geopolitical environment where many faced adversaries possessing 

or pursuing nuclear weapons.

Missile Defenses

In the post-Cold War era, conventional and nuclear forces have 

remained critical to U.S. extended deterrence and assurance strategies. 

The inclusion – albeit in fits and starts – of missile defenses in these 

strategies represents a significant change from earlier concepts that either 

did not feature missile defenses as a potential option within defense plans 

or rejected them due to concerns they would ultimately hinder, rather 

than help, efforts to defend allies and deter their enemies. For decades, 

conventional and nuclear forces represented the essential building blocks 

of U.S. plans for defending the long defense perimeter of the “free 

world.” Major missile defense projects aimed at developing the 

capability to intercept long-range Soviet missiles were seriously 

considered but ultimately rejected, in the 1960s and 1980s. This was 
72

primarily due to the large costs and uncertain outcomes associated with 

these systems, but allied objections also played a role in convincing U.S. 

policymakers and strategists that missile defenses were either 

destabilizing or represented a defense concept too far ahead of its time. 

For many U.S. allies, calculating the value of missile defenses had to 

take place within a broader assessment of geopolitics (to include the 

possible response of states such as the Soviet Union, which possessed 

means other than nuclear weapons for influencing the decision-making 

of states in Europe and elsewhere), resource constraints (given the 

astronomical costs, why not invest resources on other military 

capabilities?), arms control (a number of allies defended the ABM 

Treaty), and adversary strategy (what would prevent a determined 

adversary from using a means other than ballistic missiles to attack the 

United States or its allies?). 

By the 1990s, however, the threat of ballistic missiles in the 

hands of state leaders that seemed immune to Cold War calculations of 

deterrence began to change views in the United States and some, if not 

all, allied capitals on the role of missile defenses in extended deterrence 

and assurance strategies. The utility of TMD was recognized well before 

the 1991 Gulf War, and prompted the development of the Patriot TMD 

systems that played a prominent role in the conflict. Significantly, the 

lackluster performance of the early Patriots did not lead to a rejection of 

missile defenses as an important tool within the U.S. extended deterrence 

and assurance toolkit. The increasing scale of the ballistic missile threat, 

and rising interest of allies facing these threats in some form of 

protective shield against these attacks, prompted the United States to 

move forward with TMD and, later on, more ambitious missile defense 

systems in the post-Cold War era. 

The competing demands of addressing the geopolitical concerns 

of some allies on missile defenses, while attempting to counter the 

ballistic missile threats faced by others, complicated U.S. efforts to 

develop post-Cold War extended deterrence and assurance strategies. 

The tension between the two remained unresolved at the end of the 

George W. Bush administration, indicating that the next president’s 

decisions on missile defenses were likely to receive close scrutiny in 

foreign capitals (both allied and adversary) abroad. If allies remained 

divided on missile defenses in 2008, however, there was no denying the 

systems themselves now played an important role in U.S. deterrence, 

extended deterrence, and assurance strategies due to their unique abilities

to defend against key military assets of potential adversaries of the 

United States and its allies. 
73

Challenges to U.S. Efforts to Extend Deterrence and Provide 

Assurance

As discussed in Part 2, the credibility of U.S. extended 

deterrence and assurance strategies is a function of both the political 

resolve of U.S. decision-makers and the capabilities of the U.S. military. 

Challenges to these strategies can thus take the form of foreign parties 

(whether allies or adversaries) either doubting the willingness of the 

United States to accept the potential costs of protecting an ally or 

questioning whether the U.S. military has the right tools to defend an ally 

from potential adversary attacks. Part 2 also noted the phenomenon that 

extended deterrence and allied assurance strategies involving the same 

parties are not identical; i.e. that which assures ally X may not deter its 

adversary Y, and vice versa. In addition, the historical survey in Part 2

has found another enduring challenge faced by the United States in 

developing extended deterrence and assurance strategies: U.S. allies tend 

to resist or oppose any significant changes in associated concepts, plans, 

or policies.

This has led the United States to encounter four general types of 

challenges to its extended deterrence and allied assurance strategies that 

are derived from the combined geopolitical-military character of these 

defense guarantees: 

1) Doubts regarding the political resolve of the United States, with 

allies or adversaries asking questions about the willingness of 

U.S. leaders – and the U.S. public – to sacrifice significant 

amounts of blood and treasure, up to and including potential 

attacks on CONUS, on behalf of an ally (described as “de 

Gaulle’s Doubts”); 

2) Questions regarding whether United States either fields 

sufficient numbers of forces (conventional, nuclear, and missile 

defense), and/or employs the right mix of forces, in order to 

deter potential adversary threats to its allies (described here as 

“A Leaky Umbrella?”); 

3) Challenges associated with U.S. efforts to simultaneously meet 

the differing, and at times competing, demands of extended 

deterrence and assurance strategies (described here as “The 

Healy Theorem”), and; 

4) Challenges associated with allies generally favoring the status 

quo ante in regard to U.S. extended deterrence and assurance 

strategies.
74

Doubts about the United States’ Political Resolve (“de Gaulle’s 

Doubts”)

From the Cold War to the present day, U.S. foreign and defense 

policies have repeatedly linked the national security of the United States 

to the safety and security of U.S. allies and partners abroad. However, in 

order to convince adversaries and allies the United States is willing to 

fulfill its defense commitments, the U.S. government must convince both 

friendly and hostile foreign audiences it is willing to expend blood and 

treasure in order to protect allies and partners overseas. 

Foreign leaders are not always willing to accept these 

commitments at face value and may publicly or privately question 

whether their U.S. counterparts are willing to take risks on behalf of 

foreign states. As discussed above, President de Gaulle withdrew France 

from NATO in part due to his doubts regarding the credibility of U.S. 

extended deterrence commitments to NATO, arguing that the United 

States would never risk a Soviet nuclear strike on a major U.S. city in 

order to defend Europe from a Warsaw Pact armored offensive. Not all 

U.S. allies have shared the former French president’s skepticism of U.S. 

defense guarantees, but other foreign political and military leaders have 

shared his question of whether the United States would risk significant 

military or civilian casualties in order to defend its allies. De Gaulle’s 

question of “New York for Hamburg?” articulates a central, enduring 

challenge to U.S. extended deterrence and assurance strategies: the 

challenge of convincing an ally that U.S. leaders view threats to their

security as tantamount to threats to U.S. security, and, regardless of the 

potential costs of the ensuing military conflict, are prepared to 

immediately mobilize devastating, superior force in their defense.172

In developing assurance and extended deterrence strategies, 

plans, and operations, the United States must diligently address the 

potential allied fear – and possible adversary assumption – that in a crisis 

or conflict Washington may conclude the costs of protecting an ally 

outweigh the benefits, and renege on its security commitments. The 

United States must recognize that even close allies may question the 

political resolve of U.S. leaders when faced with an adversary that 

appears willing to go to the brink of armed conflict over an issue 

involving a third state. Allies may fear that U.S. leaders will choose selfpreservation over their alliance commitments when the potential costs of 

protecting an ally are viewed as too high. As a result of these concerns, 

there is an inherent and persistent question of credibility associated with 

U.S. extended deterrence guarantees that the United States government 

must repeatedly answer with a mix of both political assurances and 

military means. 
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Questions Regarding U.S. Military Capabilities (A ‘Leaky’ U.S. 

Umbrella?) 

A second fundamental and enduring challenge to U.S. efforts to 

assure allies and deter their adversaries is convincing foreign parties 

across the globe the United States always fields the right types and 

numbers of forces to address any potential threat to its friends abroad. 

In regard to the U.S. “nuclear umbrella” over its allies, this 

challenge stems in part from the delicate balance maintained between 

two longstanding policy commitments: 

1) the Nuclear Non-proliferation Treaty (NPT) Article VI 

commitment of the United States, and other nuclear weapons 

states recognized by the NPT, to negotiate nuclear arms control 

and disarmament accords; and 

2) U.S. security guarantees to allies and partners that the United 

States will protect them from intimidation, coercion, or attack by 

nuclear-armed adversaries. 

While U.S. allies and partners are generally in favor of efforts to 

reduce global nuclear arsenals, they also closely observe, and seek to 

inform, U.S. arms control and disarmament initiatives. Allies and 

partners are well aware that even a limited nuclear conflict would likely 

prove costly to the attacker, defender, and numerous third parties (to 

include allies of either belligerent). They often applaud U.S. efforts to 

negotiate and implement nuclear arms control accords, and many 

cooperate closely with the United States to halt further nuclear 

proliferation. As discussed above, most U.S. allies also supported the 

superpower nuclear arms control talks during the Cold War. 

However, allied support for arms control and disarmament 

initiatives is often dependent upon allies’ believing these agreements or 

projects will not fundamentally alter the U.S. nuclear umbrella covering 

their country. The superpower Cold War arms control talks were 

relatively modest in terms of overall reductions to the active U.S. nuclear 

arsenal; most allies were not concerned the potential results of these 

negotiations might either leave the United States ill-equipped to deter 

certain adversaries or lacking the right numbers and types of forces to 

defend geographically dispersed allies. The United States flatly refused 

Soviet efforts to include either allied nuclear forces or U.S. theater 

nuclear weapons (with the exception of the systems covered by the INF 

Treaty) in nuclear arms control talks. As a result, nuclear forces key to 

the defense of European and East Asian allies were not included in 

negotiations and the U.S. strategic triad remained robust in its ability to 
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address U.S. and allied defense needs. The arms control treaties of the 

Cold War and early 1990s ultimately had little to no impact on ally’s 

views of the credibility of U.S. extended deterrence and allied assurance 

guarantees. 

Responding to allied concerns regarding the ability of the United 

States to field conventional forces sufficient to their defense is also 

important for the purposes of the proliferation of nuclear weapons and 

sophisticated conventional weapons. In the late 1960s, for example, the 

removal of a division of U.S. ground forces from the ROK – part of the 

Nixon administration’s broader efforts to reduce the U.S. military 

presence in East Asia – led Seoul to quietly explore the possible 

development of its own nuclear weapons program. U.S. diplomatic 

pressure, together with assurances it would maintain a significant 

military footprint on the Korean Peninsula, ultimately convinced the 

ROK to drop these efforts. Its actions, however, revealed a connection 

between the size and strength of in-country or regional U.S. military 

forces backing extended deterrence guarantees and an ally’s interest in 

pursuing its own independent nuclear deterrent as an insurance policy 

against potential future adversary attacks. U.S. allies that fear U.S. 

security guarantees are weak or fading may seek other means to ensure 

they are protected from their adversaries – to include nuclear weapons, if 

they feel nuclear deterrence is critical to their security.

A mix of conventional and nuclear U.S. military forces, and 

deployments of these forces in sufficient strength to counter adversary 

threats, have provided a protective umbrella over U.S. allies from a range 

of threats for decades. For many allies, however, their heavy reliance on 

this umbrella leads them to closely observe U.S. decisions to shift, 

drawdown, or otherwise change the numbers or posture of U.S. military 

forces assigned to, or associated with, extended deterrence and assurance 

missions. They are deeply concerned by any move that may imply the 

United States is less able to defend them. As demonstrated by the U.S. 

experience with the ROK during the Cold War, it is important for the 

United States to rapidly respond to these concerns to prevent an ally from 

making a decision that will complicate or abrogate U.S. extended 

deterrence and assurance strategies and/or destabilize regional security. 

The “Healy Theorem:” The Perpetual Challenge of Correctly 

Tailoring Extended Deterrence and Assurance Strategies

At the conceptual level, extended deterrence and assurance 

represent two sides of the same coin. They are two facets of the same 

pledge offered by the United States: that it will use all the tools of 

national power at its disposal, to include military force, to deter 
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adversaries from coercing, intimidating, or attacking its allies and 

partners abroad. 

The interpretation of this pledge, and the value assigned to it, 

however, may differ as a result of outside parties observing this 

guarantee from differing points of view. 

The challenge posed by these different perspectives was aptly 

summarized by Lord Denis Healey, the United Kingdom’s Defence 

Secretary from 1964 to 1970, following his participation in protracted 

debates between the United States and its European NATO allies 

regarding the military capabilities required to ensure the latter’s defense 

from the Soviet bloc. With NATO’s European members invariably 

asking the United States to commit more forces to their protection than 

U.S. officials thought necessary for the purpose of deterring Moscow, 

Healey concluded “[i]t takes only 5% credibility of American retaliation 

to deter the Russians, but 95% to reassure the Europeans.”173 While the 

present geopolitical environment is significantly different from that of 

the Cold War, the “Healey Theorem” reveals two fundamental 

challenges to U.S. strategies of extended deterrence and assurance that 

remain in effect today. 

First, the Healey Theorem demonstrates that the requirements of 

assurance and extended deterrence for a discrete set of allies and their 

potential adversaries may differ markedly despite the fact the parties 

involved in both sets of strategies are the same. The United States may 

find, as it did with NATO allies during the Cold War, that the resources 

allies request for the purposes of assurance (whether measured in 

geopolitical capital, military force, or both) are greater – sometimes 

much greater – than the resources U.S. policymakers and strategists 

believe are required to deter their potential adversaries. However, for 

allies convinced they face an immediate, existential threat (such as a nonnuclear state bordering a belligerent nuclear power), the apparent failure 

of the United States to recognize the magnitude of their situation can 

raise serious doubts about the credibility of Washington as a security 

partner. As such, without necessarily adopting the allied position, it is 

important for the United States to recognize these “gaps” and respond 

with diplomatic or military means to address allied concerns, putting to 

rest any significant doubts held by their governments that the United 

States is not prepared to offer a credible strategy for their defense. 

The differing requirements of U.S. extended deterrence and 

allied assurance strategies represents a permanent challenge for U.S. 

policymakers, strategists, and planners attempting to design and 

implement these strategies on a global scale. Balancing competing allied 

demands with finite resources was often a difficult task during the Cold 
78

War, leading directly to the types of inter-alliance debates observed by 

Healey in the late 1960s. During the Cold War and afterward, the 

solution to this challenge generally required the United States to field a 

mix of military forces and engage in diplomatic offensives designed to 

convince foreign parties that U.S. extended deterrence and allied 

assurance strategies, however designed, were backed by a politically 

resolute military superpower prepared to use immediately available 

resources and bring to bear additional forces located in CONUS on 

behalf of its allies. 

The Healy Theorem also points to a second challenge that stems 

directly from U.S.-allied consultations on deterrence issues. The United 

States recognizes it is critically important to work with its allies on 

extended deterrence matters (and that these discussions are themselves 

critically important to allied assurance). Giving U.S. allies a “vote” on 

extended deterrence issues, however, also gives them an ability to 

exercise a “veto” on associated plans and strategies. This can complicate 

or even abrogate these strategies, and can cause serious problems within 

a broader alliance that depends on all members providing political and 

military support to implementing these strategies. 

One key example of a breakdown in an alliance relationship over 

questions of extended deterrence was New Zealand’s decision to become 

“nuclear free” in 1984. New Zealand had long represented both a 

staunch ally of the United States and a country that sought inclusion 

beneath the U.S. nuclear umbrella extended over close allies in the AsiaPacific. Together with the United States and Australia, New Zealand 

signed the ANZUS Treaty in 1951, confirming a common defense pact 

between the three countries. For most of the Cold War, Washington and 

Auckland cooperated closely on a range of regional defense and national 

security matters. In 1984, however, New Zealand elected a Labour 

government whose campaign platform included a pledge to make the 

country “nuclear free,” a policy that would include denying port access 

to any U.S. naval vessel capable of carrying nuclear weapons barring a 

guarantee from Washington that the vessel in question free of nuclear 

warheads. The United States, which for security reasons did not 

“confirm or deny” the presence of nuclear weapons on any ship capable 

of carrying them, refused to accede to this request (which it did not 

receive from Australia or any other ally under its nuclear umbrella). In 

subsequent bilateral discussions, New Zealand’s political leadership 

stated they hoped to retain defense ties with the United States, but not at 

the cost of its “no nuclear” policy. The United States insisted that 

nuclear deterrence, and a willingness to support nuclear forces, was 

critical to the ANZUS relationship. The impasse led the Reagan 
79

administration to state in 1985 that New Zealand had failed to meet its 

alliance obligations and U.S. defense and deterrence guarantees no 

longer applied to the country.174 

The two countries would later mend fences and even resume 

some forms of defense cooperation, but it was twenty-six years before 

the United States officially allowed New Zealand naval vessels to visit 

U.S. ports.175 The breaking of the ANZUS compact demonstrates how 

differences over extended deterrence can cause enough friction that the 

overall defense and diplomatic relationship between the two countries is 

damaged. It illustrates that a principle that is central to the Healy 

Theorem – a certain level of tension will always exist between a nucleararmed superpower and its allies. While the United States and other 

members of NATO (France, as noted above, being an important 

exception) were able to iron over most of their differences, the 

suspension of the U.S.-New Zealand alliance demonstrates that decades 

of close cooperation with an ally do not necessarily guarantee that U.S. 

bilateral or alliance relationships will survive disagreements related to 

extended deterrence or assurance strategies.176

Defending the Status Quo Ante: Allied Resistance to Changes in 

Extended Deterrence or Assurance Strategies 

From the end of the Second World War to the present day, many 

U.S. allies have generally (if sometimes reluctantly) accepted U.S. 

leadership in regard to alliance policymaking and strategizing. This 

reflects the fact that the United States represents the strongest member 

within a defense pact. Furthermore, many U.S. allies believe their 

defense requirements exceed what they can independently develop or 

afford; they depend on their alliance with the United States to meet their 

remaining needs. As a result, many U.S. allies rely on U.S. extended 

deterrence and assurance strategies to guarantee their national defense. 

Over time, these U.S. strategies – and the forces associated with them, 

particularly if deployed on an ally’s home territory – often become part 

of an ally’s long-term foreign policy and defense planning. 

As a result, once the general strategy for its assurance, and the 

extension of deterrence to its key adversaries, is established between the 

United States and a foreign ally, the latter often proves resistant to any 

significant change to either. Allied objections stem from concerns that 

any changes imply an alteration in the U.S. political resolve or military 

capabilities that are critical for their defense against foreign adversaries. 

Many allies are well aware, for example, that foreign deployments are 

frequently a target on Capitol Hill; both during the Cold War and 

afterward, Senators reviewing the U.S. defense budget have perennially 
80

pressed for allies to shoulder a greater share of the burden for their 

defense. In addition, although conflicts and contingencies have 

occasionally raised the number of U.S. troops posted overseas, in general 

over the past 20 years the United States has slowly but perceptibly 

reduced the numbers of forces permanently stationed abroad. 

As a result, any change to U.S. strategies, regardless of how 

these changes are depicted, may lead allies to question whether their 

status has somehow changed within the eyes of U.S. leaders. Allies may 

wonder if their defense concerns are still important to Washington; if 

they are surprised or unprepared by a shift in U.S. policy or strategy, they 

may conclude their views on these changes were not considered or 

deemed important. Changes in the U.S. military capabilities deployed 

in-country or in-theater may also raise issues for allies, as many are 

unable to replace these forces using resources available to their own 

militaries. 

In addition, allies resist change because many have an acute 

sense that U.S. extended deterrence and assurance strategies operate 

within a complex network of political relationships at the domestic, 

regional, and international levels – and as a result, any changes to these 

strategies can cascade throughout the entire system, often with negative 

impacts for their own country (or political regime, in cases where these 

strategies touch on sensitive local issues). They prefer maintenance of 

the status quo over changes that may give rise to some uncertainty –

whether in their own country, in the minds of adversaries, or both –

regarding whether the United States remains a reliable and predictable 

security partner. 

Most U.S. allies, however, also regard the United States as 

critical to the deterrence of significant or existential threats to their 

national security. As discussed in the historical survey above, they will 

debate but rarely flatly oppose U.S. proposals to change extended 

deterrence or assurance strategies. Significantly, withdrawals from 

defense partnerships or alliances featuring the United States are rare –

and even when they occur, the states involved often seek to retain some 

kind of defense relationship with Washington. As a result, allied 

resistance to alterations in extended deterrence and assurance strategies 

does not make change impossible, but does underline the importance of 

close communication and consultation between Washington and allied 

capitals in advance of altering or amending these strategies. Viewed 

over the time period discussed in Part 3, their interest in maintaining the 

status quo represents a phenomenon that was sometimes overlooked 

within the U.S. strategic community – despite dramatic geopolitical 

change, to include superpower détente, the end of the Cold War, and 
81

9/11. Many longtime U.S. allies remained continually reliant on their 

partnership with the United States to shield them from current enemies, 

prospective threats, regional instability, and shocks to the geopolitical 

system. 
82
83

PART 5: CURRENT U.S. EXTENDED DETERRENCE AND 

ASSURANCE POLICIES, STRATEGIES, AND FORCES

Obama Administration Extended Deterrence and Assurance Policies

The Barack Obama administration arrived in office in 2009

facing a range of pressing security challenges. With the United States 

battling al Qaeda and its affiliates around the globe, and states such as 

Iran and the DPRK continuing to threaten the United States and its 

friends abroad, effective deterrence, extended deterrence, and assurance 

strategies remained critical to U.S. security, allied security, and regional 

stability. 

The Obama White House’s development of these strategies was 

rooted in the language and understandings of these concepts developed 

over the course of previous administrations. President Obama and his 

national security team, however, viewed past efforts to develop, 

implement, and communicate these strategic concepts as too limited in 

scope, too narrow in participation, and too focused on nuclear forces. 

They were also critical of the George W. Bush administration’s approach 

to foreign policy and national security, judging its predecessor as too 

willing to embark on unilateral courses of action without properly 

consulting or cooperating with U.S. allies. They sought to adapt and 

evolve U.S. deterrence, extended deterrence, and assurance strategies to 

reflect a rapidly changing geopolitical environment where the United 

States and its allies face a broad range of potential state and non-state 

adversaries that pose threats across geographic regions and strategic 

domains. In response to these challenges, the Obama administration has 

sought to broaden the purpose, scope, actors, means and methods of 

deterrence, extended deterrence and assurance.

Obama Administration Views on Geopolitics, National Security, and 

21st Century Deterrence 

The Obama administration’s development of deterrence, 

extended deterrence, and assurance strategies is shaped by its views on 

21st century geopolitics, to include its perspective on the role the United 

States should play in international affairs and the security threats 

currently faced by the country and its friends abroad. Its perspectives on 

geopolitics, U.S. national security, and deterrence are informed by the 

following key ideas. 

The United States is the world’s sole superpower, but it cannot 

“go it alone.” The Obama administration views the United States as the 

world’s most powerful state and believes it has a responsibility to lead 
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global efforts to address geopolitical challenges such as the enduring 

threat posed by the proliferation of WMD. The administration’s 

guidance documents, however, also caution that the United States does 

not have the diplomatic capital or military resources to defeat these 

threats on its own.177 It believes the United States must take a central 

role in international security affairs, while also seeking the assistance of 

foreign allies and partners to address common threats. As former 

Secretary of State Hillary Clinton noted in 2009, “America cannot solve 

the most pressing problems on our own, and the world cannot solve them 

without America.”178 Obama administration officials often emphasize 

the importance of the United States assembling broad coalitions of likeminded actors to jointly develop and implement multilateral solutions to 

regional and global security challenges.179

Although the United States does not have any enemies among 

current major powers, the United States and its allies face a range of 

state and non-state adversaries. The Obama administration believes the 

United States has competitors, but no implacable enemies, within the 

current population of major geopolitical powers. Recognizing that the 

interests of great powers do not always align, but convinced conflict 

between them is neither necessary nor inevitable, it has sought to foster 

“strategic stability” relationships with Russia and China through 

diplomatic engagement. 

However, while the president and his national security staff are 

convinced a great power conflict is unlikely in the near-term, they also 

believe the ongoing war with al Qaeda and enduring threats from “risk 

taking” states such as Iran, Syria, and North Korea underscore the broad 

range of state and non-state adversaries that currently pose threats to the 

United States and its allies. The Obama administration also believes 

these adversaries pose a significant challenge for U.S. deterrence 

concepts. Despite the potential risk of Washington responding to armed 

provocations with overwhelming military force, these adversaries are 

willing to threaten the United States and its allies, flaunt international 

law (to include UN Security Council resolutions on WMD), and develop 

the capability to launch attacks against the United States and its friends 

abroad. As a result, the Obama administration has questioned the 

effectiveness of earlier U.S. deterrence and extended deterrence 

strategies for addressing the challenges posed by these state actors. 

The president and his national security staff have also argued 

that deterrence by punishment does not apply to al Qaeda and its allies, 

which are committed to violently attacking the United States and its 

friends abroad regardless of the risks and costs involved. This also 
85

applies to nuclear weapons, which have no deterrence value against an 

opponent whose religious or ideological views place high value in 

harming an enemy by any means necessary, to include suicide or highattrition attack strategies. The 2010 NPR states that the United States 

must assume that al Qaeda would immediately use any nuclear capability 

it acquired, despite the U.S. ability to respond with overwhelming 

force.180 Other guidance documents, such as the 2010 QDR and 2012 

DSG, expressly separate discussions of deterring potential adversaries 

from those focused on defeating al Qaeda. While deterrence by 

punishment strategies may be of little use for countering al Qaeda and 

other non-state actors, the Obama administration believes deterrence by 

denial approaches can prevent attacks. In some cases, missile defenses 

may play a role; the 2010 Ballistic Missile Defense Review notes that the 

United States and its allies may face ballistic missile-armed terrorist 

organizations in the future and that this would “raise profound new 

questions about regional security.”181 Without expressly linking missile 

defenses to deterring this specific threat, the guidance document does 

repeatedly state that these defense systems play a critical role in 

protecting regional allies and deterring their adversaries from launching 

missile attacks.

The U.S. military must “rebalance” its forces and its 

geostrategic focus. The Obama administration entered office believing 

the United States needed to realign its national and international security 

priorities after years of fighting in Iraq and Afghanistan. “Rebalancing 

the Force,” for example, was a major theme of its 2010 Quadrennial 

Defense Review (QDR).182 The United States, it argued, was bogged 

down in Afghanistan, should not have invaded Iraq, relied too often on 

its own forces (vice developing true war fighting coalitions with allies), 

and possessed a military force that remained too heavily oriented toward 

ground and nuclear forces while lacking capabilities devoted to areas 

such as cyber warfare. Moreover, entering office during a time of 

international and domestic economic crises, and facing fiscal challenges 

throughout its first term, the Obama administration also sought to cut 

military spending while protecting key capabilities.183 For the purposes 

of better addressing contemporary threats and conserving scarce 

resources, the Obama administration pressed for the military to adapt its 

current forces, and develop future capabilities, with a focus on “mobile” 

(or “relocatable”) and “flexible” forces that could be rapidly moved or 

re-calibrated to address shifting, evolving threats wherever they 

emerged.184 Later within its first term, it would also apply the concept of 

a “rebalance” to also underline a geographic shift toward developing 
86

strategies and plans for defending allies and preparing for conflicts in the 

Asia-Pacific. From the outset, the Obama administration sought to make 

a break from what it viewed as the outdated strategies of the Cold War –

which it believed still exerted a pull on U.S. defense thinking (ironically, 

an argument it shared with its predecessor) – and also what it considered 

the failed strategies of the “war on terror.” As such, “rebalancing” – in 

terms of realigning strategic defense priorities and shifting attention to 

the Asia-Pacific – carried with it implications for deterrence, extended 

deterrence, and assurance strategies.

The Prague Initiative. President Obama’s April 2009 speech 

delivered to a large crowd assembled in Prague’s Hradcany Square 

represented one of his administration’s key first term foreign policy 

addresses and its central statement on the role of nuclear forces in its 

development of national security policy and military strategy. The 

administration deliberately selected Prague, a city that remained behind 

the Iron Curtain during the Cold War but was now the capital of an 

important U.S. ally and member of NATO, as the location for the speech. 

The president and his national security staff intended to signal the 

administration’s determination to move beyond Cold War paradigms for 

addressing nuclear threats to approaches that it believed better suited for 

combating current nuclear challenges. Four years later the president 

would reiterate his intent to press for global nuclear reductions in a 

speech delivered at Berlin’s Brandenburg Gate, stating that the United 

State could further reduce its numbers of deployed nuclear weapons and 

calling for additional nuclear arms negotiations with the Russian 

Federation.185

In his Prague address, President Obama stated that U.S. nuclear 

strategy was out of date, failing to reflect broad changes in geopolitics, 

the improved state of U.S.-Russian relationship, and the current threat 

environment. A nuclear arsenal originally designed for the Cold War 

was poorly suited for the security challenges posed by current 

adversaries threatening the United States and its allies. Nuclear 

deterrence still remained important to deterring adversaries armed with 

nuclear weapons, and the president pledged that the United States would 

continue to maintain a “safe, secure, and effective arsenal to deter any 

adversary and guarantee that defense of our allies.” He was determined, 

however, to “reduce the role of nuclear weapons in our national security 

strategy, and urge others to do the same” and planned to begin a new 

round of nuclear arms control talks with the Russian Federation. Beyond 

U.S.-Russian nuclear reductions, he also hoped to lead broader, long-
87

term efforts to “seek the peace and security of a world without nuclear 

weapons.”186 

This goal reflected his conclusion that nuclear deterrence alone

could never fully guarantee the safety and security of the United States. 

Nuclear deterrence might not apply to dictators or terrorists who might 

attack the United States or its allies despite the prospective costs of a 

U.S. military response. As such, U.S. efforts to counter these threats 

needed to urgently pursue two tracks. First, the United States needed to 

spearhead a range of multilateral nonproliferation and 

counterproliferation initiatives to prevent these types of actors from 

acquiring materials, technology, and delivery systems associated with 

nuclear weapons and other forms of WMD. Moreover, if the size, 

posture, or declaratory policy of U.S. nuclear forces represented potential 

obstacles to securing broad international cooperation on these initiatives, 

the United States would take steps – via arms control or other means – to 

allay these concerns. Second, the United States and its allies needed to 

develop missile defense systems and concepts to address those potential

adversaries that fielded, or were attempting to develop, WMD and 

ballistic missiles capable of delivering these types of weapons. Close 

cooperation with allies such as the Czech Republic, which had 

volunteered to host components of a NATO missile defense system 

intended to shield the alliance against future missile threats from 

countries such as Iran, were vital to developing this critical deterrenceby-denial capability.187

The Obama administration’s subsequent strategic guidance 

documents addressing nuclear forces and their role in deterrence, 

extended deterrence, and assurance strategies, have reflected – and 

expanded upon – the key themes articulated within the Prague address. 

For example,

1) The U.S. will maintain a “safe, secure, and effective” nuclear 

deterrent, but will reduce its role in defense planning and reduce 

the size of its arsenal; 

2) The most pressing nuclear threats facing the United States and 

its allies are best addressed through the mechanisms of nuclear 

nonproliferation and arms control; 

3) Countering the threat posed by ballistic missile and nuclear 

weapons proliferation required the United States and its allies to 

pursue improved missile defenses. 

The 2010 NPR, for example, asserted that the United States could reduce 

its nuclear arsenal in favor of other types of forces without destabilizing 

its deterrence relationships with other nuclear powers, negatively 
88

impacting its extension of nuclear assurance guarantees to its allies, or 

otherwise damaging U.S. national security:

fundamental changes in the international security 

environment in recent years – including the growth of 

unrivaled U.S. conventional military capabilities, major 

improvements in missile defenses, and the easing of 

Cold War rivalries – enable us to fulfill those objectives 

at significantly lower nuclear force levels and with 

reduced reliance on nuclear weapons.188

In the specific case of the Russian Federation – the only current 

U.S. peer competitor in terms of nuclear forces – President Obama 

believes the country’s current strategic relationship mitigates the need for 

the United States to maintain “strict numerical parity” with the latter’s 

nuclear arsenal.189 During his first term, for example, he elected to 

reduce some of the destructive power of U.S. Minuteman III ICBMs 

(removing two of the three nuclear warheads carried by these delivery 

systems), stating this move would encourage greater stability in the U.S.-

Russia nuclear deterrence relationship.190 The Obama administration 

was also adamant throughout the New START ratification process that 

the treaty’s mandated nuclear reductions would have no impact on the 

ability of the United States to deter, or extend deterrence against, the 

Russian Federation or other nuclear powers.191 It also stated, however, 

that stability between the two states remains tied to each side remaining 

confident in their ability to deter the other, stating “large disparities in 

nuclear capabilities could raise concerns on both sides.”192 

In response to contemporary nuclear threats, the Obama 

administration has led multilateral efforts to secure global nuclear 

materials and counter nuclear terrorism, and attempted to press the 

international community to move forward on negotiating a 

comprehensive treaty halting the production of fissile materials (to date, 

with limited success, in part due to opposition from Pakistan). It also 

continued and sought to expand programs such as the Proliferation 

Security Initiative (PSI), a multilateral counterproliferation initiative that 

included combined efforts to track and interdict the illicit transit or 

transfer of WMD-related items. These efforts reflect its assessment that 

the U.S. nuclear arsenal – while remaining important for deterring, and 

extending deterrence against, established nuclear powers – ultimately 

cannot guarantee protection to the United States or its allies against “risk 

taking” regional powers or non-state actors attempting to develop or 

acquire nuclear weapons. It has sought to supplement the deterrence 

provided by these forces against some (but not all) threats posed by the 

nuclear weapons of potential adversaries with arms control, 
89

nonproliferation, and other approaches that it believes will reduce or 

prevent the capacity of these adversaries to wield nuclear threats. 

The United States must expand its global network of defense 

relationships by reinvigorating existing alliances and establishing new 

security partnerships. After the Second World War – and for the duration 

of the Cold War – the United States established defense alliances and 

security partnerships across the globe to bolster U.S. national security, 

protect U.S. friends abroad, and contribute to broader efforts to secure 

and stabilize the international geopolitical system. 

The Obama administration has repeatedly reaffirmed the 

importance of these defense relationships in the 21st century. In addition 

to attempting to increase the depth and breadth of engagement on 

defense issues with longstanding allies, it also hoped to negotiate new 

security partnerships in vital strategic regions such as the Asia-Pacific. 

While recognizing the importance of these relationships, 

however, the Obama administration also sought to ease the U.S. share of 

the burden for protecting allies across the globe. President Obama and 

his national security team have pressed for U.S.-allied defense 

relationships to achieve greater balance rather than remain dominated, 

whether in terms of overall forces or responsibilities, by the U.S. 

military. Whether through increasing combined training and exercises,

approving the sales or transfers of military equipment, or devolving 

greater roles and responsibilities for combined defense matters to U.S. 

allies, the Obama administration has sought to increase the role and 

responsibilities of foreign governments in the development and 

implementation of defense plans and policies.193 Moreover, this process 

includes greater allied participation in matters related to U.S. extended 

deterrence and assurance strategies, to include matters relevant to the 

role of U.S. nuclear forces within these strategies.194 

The United States will extend deterrence and provide assurance 

across all key strategic domains, to include space and cyber space. In 

the 21st century, the United States and its allies possess critical assets –

and face potential threats from state and non-state actors – across land, 

sea, air, space, and cyber space domains. In response, the United States 

must assure allies it can protect them against direct attacks on their 

sovereignty and national assets across these five strategic domains, and 

develop credible deterrence strategies against their potential adversaries 

across these domains. In the 21st century, it may no longer be sufficient 

to provide forces capable of defending an ally’s land borders from 

external attack; with potential adversaries developing anti-satellite 
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capabilities, and conducting cyber incursions and attacks against U.S. 

and allied government, military, and industry cyber assets, the United 

States must view the development of extended deterrence and assurance 

strategies as a multi-dimensional problem set requiring the full spectrum 

of defense tools and operations to defend allies against a broad range of 

attacks. 

The Obama administration’s 2010 National Space Strategy, for 

example, states that the U.S. government will take steps to “reassure 

allies of U.S. commitments to collective self-defense” of their space 

systems and operations, and its 2011 National Security Space Strategy

states that the United States and its allies will “explore the development 

of combined space doctrine ... [to] enable the collaborative sharing of 

space capabilities in crisis and conflict.”195 In addition, the United States 

is also beginning to develop policies and strategies for assuring U.S. 

allies they are protected against adversaries’ efforts to damage key 

national assets via cyber-attacks. In 2011, the United States and 

Australia expanded the 1951 ANZUS to include cyber-attacks, 

committing each state to come to the defense of the other in the event of 

a major adversary cyber-attack (such as an effort by an enemy state to 

use cyber warfare to disable U.S. or Australian national military 

communication systems).196

The United States must protect the “global commons” and deter 

any effort to restrict the free use of these areas across all five key 

strategic domains (land, sea, air, space, and cyber space). In the 21st

century the “global commons” (“those areas beyond national jurisdiction 

that constitute the vital connective tissue of the international system”) are 

central to the national security and economic prosperity of the United 

States and its allies, which rely upon the freedom and safety of 

international waters, airspace, outer space, and cyber space for the 

purposes of trade, transit, and communications.197 The freedom and 

openness of the global commons, however, leaves it vulnerable to 

exploitation. As the only geopolitical actor capable of global power 

projection, and the democracy best-equipped to rally multilateral 

coalitions to address common security problems, the Obama 

administration believes the United States has both a vested interest and a 

responsibility to take the lead in protecting the global commons. This 

requires the United States to develop strategies for deterring antiaccess/area denial (A2/AD) initiatives by state or non-state actors 

attempting to seize control and/or deny the free use of these strategically 

vital domains.198
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The United States must “tailor” its deterrence, extended 

deterrence, and assurance strategies. The Obama administration believes 

a broad range of actors threaten U.S. allies across the globe. These 

adversaries differ broadly in terms of their worldviews, geopolitical 

goals, defense strategies, and offensive and defensive capabilities. With 

deterrence representing a phenomenon that operates within the mind of a 

potential adversary and affects their calculations on the costs and benefits 

of potential actions, this diversity of adversaries – state and non-state, 

major powers and regional powers – suggests that the exercise of 

deterrence across this rogue’s gallery will differ from actor to actor. 

Similarly, the Obama administration also recognizes that the United 

States has alliances with a diverse population of states, each with its own 

opinion regarding their national security requirements. In addition, the 

defense capabilities of these allies vary widely. This has led the Obama 

administration to conclude the United States must develop a variety of 

assurance and extended deterrence strategies to simultaneously assure its 

friends and deter their enemies. 

This conclusion has led it to strongly support the idea developed 

by experts at USSTRATCOM and the DoD that the United States must 

develop “tailored deterrence” strategies to address 21st century threats. 

The 2006 DoD Deterrence Operations Joint Operating Concept (DO 

JOC), for example, emphasized the importance of developing deterrence 

strategies “tailored” to address situation-dependent variables and the 

unique requirements of each individual adversary:

Because the perceptions and resulting decision calculus 

of specific adversaries in specific circumstances are 

fundamentally different, our deterrence efforts must also 

be tailored in character and emphasis to address those 

differences directly.199

Current administration guidance carries this logic a step further: 

in addition to tailored deterrence strategies, the United States must also 

pursue tailored extended deterrence and tailored assurance strategies. 

The 2010 QDR, for example, links the credibility of U.S. security 

guarantees to the U.S. government’s ability to develop strategies 

expressly designed to deter the unique threat posed by each potential 

adversary of a U.S. ally: 

Credibly underwriting U.S. defense commitments will 

demand tailored approaches to deterrence. Such 

tailoring requires an in-depth understanding of the 

capabilities, values, intent, and decision making of 

potential adversaries, whether they are individuals, 

networks, or states.200
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Administration officials also emphasized the importance 

of tailoring U.S. assurance strategies featuring capabilities such 

as missile defenses to the specific needs and requirements of 

each individual ally:

Regional approaches must be tailored to the unique 

deterrence and defense requirements of each region, 

which vary considerably in their geography, in the 

history and character of the threat, and in the military-tomilitary relationships on which to build cooperative 

missile defenses.201

Although the 2006 DO JOC predates the administration, 

its views on “tailoring” deterrence strategies resonated with an 

administration looking to both “rebalance” U.S. military forces 

to better match contemporary threats and also improve U.S. 

engagement with allies and partners abroad. The term 

“tailoring” appeared to reflect the administration’s interest in 

tightly focusing defense planning to efficiently use available 

resources. It also offered a possible means for improved 

engagement with U.S. allies on defense and deterrence issues. 

The administration viewed the practice of tailoring deterrence 

strategies as a process that could lend itself to substantive U.S.-

ally dialogues convened to develop relevant plans and policies. 

These combined efforts would reassure U.S. allies the United 

States’ desired their full participation in building effective 

strategies for their defense while also improving the focus and 

fidelity of extended deterrence strategies integrating the unique 

information and intelligence available to allied actors. 

Obama Administration Extended Deterrence and Assurance 

Strategies

Extended Deterrence Strategies 

The Obama administration, as with other post-Cold War 

presidencies, has found itself within a constantly evolving geopolitical 

environment where complex regional dynamics, the ongoing process of 

globalization, and the rapid pace of technological change result in the 

United States and its allies facing potential adversaries whose character 

and capabilities can rapidly evolve in a short period of time. Based on its 

assessment of 21st century security threats, the Obama administration has 

sought to expand the scope of U.S. deterrence and extended deterrence 

strategies while also simultaneously improving the fidelity of these 
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strategies with regard to the specific, near-term threats posed by “risk 

taker” states.

Scope. The Obama administration has sought to expand the 

scope of U.S. extended deterrence strategies into new strategic domains, 

asserting the United States must address the fact that the national security 

of its allies is increasingly dependent on strategic domains beyond land, 

sea, and air. The United States has long extended deterrence to protect 

the sovereign territory of its allies from their potential adversaries. 

Similar to the United States, however, allied governments, militaries, 

economies, and national life are increasingly reliant on satellites, 

computer networks, and a wide variety of technologies dependent on 

both. In addition to defending allies against attacks by land, sea, and air, 

the Obama administration believes the United States must also extend 

deterrence to protect its friends from attacks in space and cyber space.

202

Beyond attacks aimed at U.S. allies, it has also stated that the United 

States must seek to extend deterrence over the “global commons,” 

protecting the free access of the United States and its allies to 

international waterways and other areas that are outside of national 

sovereign control and, by international law, open to use by all lawabiding state actors.

Focusing on the Threat of “Risk Taker” States. The Obama 

administration has also sought to focus its extended deterrence strategies 

on the specific actors and actions that represent the most critical threats 

to U.S. friends abroad. While citing the need to remain flexible in 

addressing a range of potential threats to U.S. allies and partners, they 

have also argued that the United States must be more responsive in 

reacting to its friends’ immediate security concerns. At present U.S. 

extended deterrence strategies are focused on “risk-taking” regional 

powers, particularly those armed with WMD and the means to deliver 

them. These actors are viewed as posing an immediate threat to U.S. 

allies and regional stability. 

Current guidance documents discussing deterrence issues and 

strategies, for example, focus on Iran and North Korea, states with 

nuclear weapons programs, growing ballistic missile arsenals, and 

leaders who have demonstrated a willingness to take significant risks in 

order to intimidate, coerce, or attack U.S. allies and partners within their 

region.203 The administration’s 2010 BMDR states that deterrence by 

punishment strategies may be of limited utility for these type of actors; 

their leaders may believe their missile arsenals allow them to effectively 

deter the U.S. government by threatening attacks against the United 
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States, U.S. allies, and/or U.S. forces deployed abroad, despite the ability 

of the U.S. military to respond with devastating force. As the BMDR 

stated,

Risk-taking leaders [in Iran or North Korea] may 

conclude that they can engage the United States in a 

confrontation if they can raise the stakes high enough by 

demonstrating the potential to do further harm with their 

missiles.

204

In response, the United States should adapt its extended deterrence 

strategies to develop more deterrence by denial options (such as missile 

defenses) to address the challenge posed by risk taker states. 

In the past, major powers such as Russia and China were also 

singled out as potential adversaries of U.S. allies and were often the 

focus of U.S. extended deterrence strategies. The Obama 

administration’s 2010 NPR, however, discusses both actors within the 

context of “maintaining strategic deterrence and stability at reduced force 

levels” rather than as potential adversaries of the United States or U.S. 

allies.205 The term “extended deterrence” is not expressly used to 

describe either country within the review. Instead, the emphasis within 

this guidance document, the 2013 Report on Nuclear Employment 

Strategy (2013 RENS), and other administration statements on U.S.-

Russia and U.S.-China strategic issues, is on the importance of 

establishing a “strategic stability” relationship with each country.206 In 

2012, for example, the Obama administration initiated a series of 

“strategic stability” dialogues with Moscow, to include discussions on 

nuclear forces and missile defenses. While this shift in emphasis does 

not imply a weakening of commitment to extend deterrence against any 

actor that threatens a U.S. ally, it does reflect an assessment that the 

present focus of U.S. extended deterrence policies and strategies should 

be on risk-taking actors posing complex, near-term threats to the United 

States and its friends abroad.207 

The Obama administration has also emphasized the importance 

of the United States operating across all five strategic domains and, in 

doing so, maintaining the freedom of the global commons. As such, the 

U.S. military must extend deterrence against any party – state or nonstate – attempting to carry out A2/AD actions or strategies. Recent 

guidance has cited Iran and China as actors that will “pursue asymmetric 

means” in order to restrict U.S. access to various areas in an effort “to 

counter [U.S.] power projection capabilities.”208
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Extended Deterrence: Military Force Requirements 

The Obama administration views extended deterrence strategies 

as utilizing three types of military forces – conventional, missile defense, 

and nuclear – supported by space and cyber enablers:

The United States remains committed to our Allies’ 

continuing security through our policy of extended 

deterrence. We seek to reiterate this message as often as 

possible, including through efforts to bolster regional

deterrence architectures around the world. We are 

building regional cooperative missile defenses, forwarddeploying U.S. forces, and maintaining what is 

commonly referred to as the “nuclear umbrella.”209

As noted above, however, in regard to the relative balance 

between these three types of forces, it is also committed to reducing the 

U.S. “reliance” on its nuclear arsenal in favor of conventional and 

missile defense forces.210 This is reflected in both numbers and role in 

defense strategy.

Conventional Forces. The presence of U.S. conventional forces 

on allied territory, either on fixed bases or as part of a regular rotation, 

extends deterrence against their potential adversaries. In addition to the 

combat power these forces can bring to bear against any enemy 

attempting to harass a U.S. ally, the prospect of additional U.S. military 

assets rapidly bolstering any American troops that come under fire 

abroad can serve as an effective deterrent of many actors that might 

otherwise initiate action against a government friendly with Washington. 

The Obama administration has also highlighted three other 

characteristics of U.S. conventional forces that are particularly important 

for deterring the potential adversaries of U.S. friends abroad:

Flexible options. Some potential adversaries may seek to use 

force asymmetrically, or in a manner below what they consider the likely 

threshold for a U.S. response, in order to coerce, intimidate, or attack 

U.S. allies and partners. By deploying a range of scalable response 

options across different strategic domains, the U.S. military will clearly 

signal to potential adversaries that any provocation against an ally or 

partner will result in an effective, proportionate strike quickly negating 

any perceived gains.211

Stand-off and long-range strike capabilities. The ability of U.S. 

conventional forces to launch precision strikes from platforms out of the 

reach of actors such as risk taking regional powers serves as an important 
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means for preventing attacks on allies and partners and represents a 

powerful deterrence-by-punishment capability.

Training Allied Forces and Boosting Interoperability. The U.S. 

military’s ability to strengthen the conventional capabilities of allies and 

partners through training and other measures can deter adversaries by 

forcing them to devote greater resources to address the improved 

effectiveness of allied militaries. In addition, combined operations (or 

even the possibility that U.S. and allied forces can combine quickly and 

easily) can deter potential adversaries of U.S. allies, presenting them 

with a fully integrated military force capable of causing unacceptable

damage to their own conventional forces.212

Robust Levels of Pre-Positioned Munitions and Supplies.

Logistic and supply networks can also play a role in deterring 

adversaries. If U.S. conventional forces deployed abroad have ready 

access to a range of munitions and supplies stored in theater (or easy to 

quickly acquire from elsewhere) an adversary may elect not to initiate a 

military action that could meet with a rapid, decisive response from the 

United States.213

Nuclear Forces. The Obama administration is committed to 

reducing the overall role and number of U.S. nuclear forces. This 

reduction, however, must be balanced against the critical importance of 

maintaining the ability to extend nuclear deterrence against potential 

nuclear-armed adversaries. The 2010 NPR thus balances a call for 

reducing the U.S. nuclear arsenals with a pledge that the United States 

will maintain nuclear forces capable of imposing “unacceptable costs” 

against any nuclear-armed adversary contemplating use of these weapons 

against either the United States or U.S. allies and partners.214 

Within the U.S. nuclear force, certain systems and weapons are 

more closely associated with the extended deterrence mission than 

others. Regional states such as the DPRK and Iran act in a destabilizing 

and provocative manner despite the massive conventional and nuclear 

force imbalances between them and the United States, calculating they 

can take a range of actions to undermine U.S. allies and partners without 

necessarily provoking a U.S. response. Against this type of geopolitical 

actor, extending deterrence requires a visible demonstration of nuclear 

capabilities in theater to signal that the United States is committed to 

deterrence strategies that will directly and openly confront – and if 

necessary defeat – any actor attempting to use nuclear forces for the 

purposes of regional coercion or aggression.

215
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This underlines the importance of mobile, visible, forwarddeployable nuclear forces for the purpose of extending deterrence. At 

present, this combination of key characteristics is only found in U.S. 

nuclear-capable aircraft: B-52 bombers, B-2 bombers, and dual-capable 

aircraft – F-15Es, F-16s, and eventually F-35s.216 These nuclear delivery 

systems can either carry the B83-1 nuclear gravity bomb (bombers), B61 

nuclear gravity bomb (bombers and DCA), or the AGM-129A cruise 

missile (B-52H only).217 Unlike SLBMs (usually invisible) and ICBMs 

(fixed in place), the United States can visibly deploy nuclear-capable 

aircraft to a region during a period of crisis. As a result, bombers 

represent the only leg of the U.S. strategic nuclear triad capable of 

clearly and directly signaling the U.S. intent to exercise nuclear 

deterrence against an actor attempting to use nuclear weapons to coerce 

or intimidate a U.S. ally or partner.218 In addition, following the 

retirement of the TLAM-N, DCA represent the only “non-strategic” 

nuclear delivery system within the U.S. arsenal that has these qualities of 

mobility, visibility, and flexibility.219

Missile Defenses. The Obama administration views missile 

defense systems as playing an increasingly vital role in U.S. extended 

deterrence strategies. Ballistic missiles represent the primary means for 

actors such as Iran and the DPRK to threaten U.S. allies and partners and 

attempt to deny U.S. freedom of action within areas they view as 

potential national spheres of influence. Both countries have invested 

heavily in the development, testing, and fielding of ballistic missiles 

arsenals, reflecting the high value they place in these systems. 

Missile defenses provide an active defense, deterrence-by-denial 

option against this adversary capability. They can track, intercept, and 

destroy ballistic missiles before they strike the territory of U.S. allies or 

U.S. forces deployed abroad. The Obama administration views missile 

defenses as particularly important for extending deterrence because it is 

uncertain whether U.S. offensive strike options are viewed as a credible 

deterrent by Iranian or DPRK leaders.220 The deployment of missile 

defenses can shield U.S. friends abroad from these or other “risk taking” 

states prepared to launch a ballistic missile attack against U.S. allies 

despite the potential consequences of a U.S. military response. Indeed, 

the Obama administration hopes that by continuing to improve missile 

defenses, the United States and its allies and partners may even deter 

potential adversaries well before contemplating a potential missile 

launch. A state actor facing highly effective U.S. regional missile 

defenses may simply elect not to devote significant resources to 

developing a capability that will fail to achieve any results in battle.221
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The Obama administration and Joint Chiefs of Staff have 

expressly directed that the development of missile defenses – and 

associated strategies – be tailored to deter specific threats to U.S. 

regional allies and partners.222 The U.S. government’s current “phased 

adaptive approach” to regional missile defenses “is tailored to the threats 

unique to that region, including their scale, the scope and pace of their 

development, and the capabilities available and most suited for 

deployment.”223 The Obama administration believes this approach will 

allow the United States to effectively extend deterrence by directly 

matching U.S. missile defense capabilities – which are improving, but 

remain limited in numbers of key components such as interceptors –

against specific, pressing threats faced by allies.

Allied Assurance Strategies

 The Obama administration recognizes the critical importance of 

developing effective extended deterrence and allied assurance strategies. 

In order to assure allies they are protected against 21st century security 

threats, it has consciously sought to develop “regional security 

architectures” and increase allied involvement within processes 

developing deterrence and defense strategies. 

Building Regional Security Architectures. A key aspect of the 

current U.S. approach to allied assurance is focused on building, 

bolstering, and sustaining regional security architectures that allow for 

the seamless development of combined defense plans and operations 

with its allies. This will improve the latter’s capacity for self-defense 

and ease the ability of the United States to flow conventional, nuclear, 

and missile defense forces to a region in response to sudden crises or 

conflicts.

With allies and partners spread across the globe, the United 

States has often adapted extended deterrence and assurance policies and 

plans to reflect region- or country-specific requirements. From the close 

of World War II to the present day, the development of regional security 

arrangements through a network of agreements, overseas bases, and 

defense cooperation has represented a central component of U.S. efforts 

to extend deterrence against adversaries and assure allies and partners. 

The United States has long recognized that the country must build and 

maintain these relationships for the purposes of U.S. national security, 

regional stability, and international peace.224 

The Obama administration’s views on extended deterrence and 

assurance are rooted within this tradition, but it has also sought to 

reinvigorate existing regional security arrangements, increase the depth 
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and breadth of cooperation with allies (with an eye toward increasing the 

latter’s involvement), and also build new partnership networks 

encouraging greater involvement between foreign states as a means to 

improve their defenses and reduce their reliance on the United States. It 

hoped to encourage greater cooperation, for example, between allies and 

partners in East Asia and the Persian Gulf. In both regions past history, 

intra-regional rivalries, capability gaps, domestic politics, and other 

factors had often forced the United States to play a central coordinating 

role without the benefit of any alliance or partnership structure to 

manage regional defense roles, responsibilities, plans, or strategies. 

The administration also believed that building, improving, or 

expanding upon regional defense architectures would greatly aid the 

flexibility of U.S. forces, putting into place the political, strategic, and 

physical mechanisms allowing the United States to quickly flow or surge 

assets between theaters. This would help the United States make the 

most efficient and effective use of critical, but scarce, defense resources 

(such as missile defenses). 

For the Obama administration, improving regional security 

architectures boosts the ability of the United States to assure its allies by 

improving the means and methods for close allied engagement with 

Washington on security challenges while also creating mechanisms 

encouraging greater cooperation and involvement on defense matters 

across the non-U.S. participants within a particular architecture. As 

such, in theory these updated and expanded architectures would 

demonstrate the United States’ enduring political and military 

commitment to defending regional allies without necessarily requiring 

significant numbers of permanently stationed military forces in theater.

Boosting Allied Involvement in Developing Defense and 

Deterrence Strategies and Plans. A key recommendation of the 2010 

NPR was that the United States should “expand and deepen consultations 

with allies” on the role of U.S. nuclear forces within extended deterrence 

concepts and plans relevant to their defense.225 The Obama 

administration, for example, pledged that U.S. officials will hold 

discussions with their counterparts in allied and partner states before 

shifting or removing any nuclear forces associated with extended 

deterrence: “[n]o changes in U.S. extended deterrence capabilities will be 

made without close consultations with our allies and partners.”226 

Furthermore, it has also stated the United States will consult with allies 

prior to making any further changes in declaratory policy: “the United 

States will consult with allies and partners regarding the conditions under 
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which it would be prudent to shift to a policy under which deterring 

nuclear attack is the sole purpose of U.S. nuclear weapons.”227

In seeking broader and deeper allied engagement on policies and 

strategies centrally important to the national security of friendly regimes 

facing nuclear threats, the Obama administration seeks to make U.S.-

allied defense strategies a truly collaborative, cooperative enterprise. In 

the case of NATO, where clear mechanisms for joint development of 

these strategies exist, it has sought to reinvigorate allied participation in 

discussions on nuclear extended deterrence across the alliance. In East 

Asia, where the United States has long maintained a nuclear umbrella, 

but, lacking any body analogous to NATO’s Nuclear Planning Group, IT 

did not necessarily hold detailed discussions on deterrence issues with its 

regional allies. It has established an Extended Deterrence Policy 

Committee (EDPC) with the ROK and an Extended Deterrence Dialogue 

(EDD) with Japan. With the region including three non-U.S. nuclear 

powers, these bodies serve as mechanisms for ongoing dialogues on 

extended deterrence and assurance matters with these non-nuclear 

regional allies.

By increasing engagement with allies on nuclear deterrence 

matters, and by encouraging them to take a more active role in 

developing broader strategies and plans for deterring their adversaries (to 

include forces such as missile defenses), the Obama administration 

believes it can achieve a number of objectives that bolster U.S. assurance 

strategies. First, it believes improved communication with allied leaders 

on these topics (via new mechanisms such as the EDPC and EDD, for 

example) allows the United States to better address allied security 

concerns and explain deterrence concepts, operations, and forces. This 

can be particularly important as these leaders change over time; newly 

elected allied governments may wish to confirm that deterrence 

guarantees remain in place, or ask how they have adapted to meet recent 

threats, while newly promoted military commanders may have little 

familiarity with U.S. nuclear deterrence strategies (particularly if their 

own armed forces lack nuclear weapons). Second, the Obama 

administration also believes many allies possess unique information and 

insights on potential adversaries that they can share with the United 

States during these consults, significantly improving its ability to tailor 

its deterrence strategies. Allies in turn will derive assurance from the 

United States taking its views into account in developing plans and 

deploying forces well-suited to address adversary threats. Third, by 

better integrating allies with the plans, operations, and forces 

implementing extended deterrence strategies, both countries can make 

the most efficient use of their available defense resources. This will help 
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address allied concerns regarding the U.S. military’s “re-balancing” 

(which may include reductions to the U.S. forces within their region or 

country) and increase confidence in their own ability to deter regional 

adversaries. 

Allied Assurance: Military Force Requirements

Similar to extended deterrence strategies, U.S. assurance 

strategies also rely on a mix of conventional, nuclear, and missile 

defense forces, enabled by space and cyber assets.

Conventional Forces. Documents such as the 2010 QDR state 

that the visible presence of U.S. conventional forces – whether provided 

by permanent basing, regular rotations, or forward deployment – remains 

critically important to assuring U.S. allies.228 For many U.S. friends 

abroad, U.S. “boots on the ground” retain the assurance value held 

throughout the Cold War, representing a tangible symbol of the United 

States’ guarantee it is willing to risk American lives for the sake of an 

ally’s protection against adversary aggression. 

The United States also assures allies through combined training 

and exercises, programs and activities that increase operability, and sales 

or transfers of military equipment. These steps ensure that U.S. allies 

believe both parties can act cohesively and decisively in the event of 

conflict or crisis, rapidly countering adversary threats to their security.

Nuclear Forces. The Obama administration seeks to 

simultaneously reduce the numbers and role of its nuclear forces while 

also assuring allies that it retains robust nuclear capabilities for their 

defense. In particular, it believes that allied assurance requires the United 

States to retain nuclear-capable delivery systems that are both mobile and 

visible. Mobile forces allow the United States to quickly move nuclear 

assets to any area facing a nuclear crisis, quickly allaying any allied 

concern the United States might be slow to respond to a nuclear threat. 

Visible forces – whether forward deployed or on regular rotation or 

patrol – can provide a clear demonstration to an ally is covered by the 

U.S. nuclear umbrella. In addition, many U.S. allies believe that 

potential adversaries track or notice the presence of U.S. nuclear-capable 

delivery systems in theater or on the territory of a friendly state, and will 

refrain from acts that could lead to a nuclear confrontation with a 

superpower. As such, the 2013 RENS expressly links allied assurance 

with U.S. nuclear-capable aircraft (bombers and DCA).229 

The Obama administration also links the U.S. ability to assure its 

allies they are covered by a nuclear umbrella with broader goals of 
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encouraging regional stability and preventing nuclear proliferation. It 

asserts that non-nuclear allied states highly confident in the level of 

protection afforded them by the U.S. nuclear guarantees will not seek to 

develop their own independent nuclear arsenals. Moreover, it also states 

that potential adversaries of U.S. allies contemplating development of 

nuclear weapons may observe the United States’ firm commitment to

extended nuclear deterrence, assess that a nuclear weapons program will 

not improve (and may ultimately detract from) their ability to influence 

regional affairs, and elect not to pursue this capability.230

Within the context of NATO, the alliance’s nuclear-sharing 

arrangements remain a key component of assuring member states of the 

U.S. commitment to their defense. These arrangements continue to bring 

together U.S. and NATO forces for joint exercises, training, and planning 

for nuclear operations. This close cooperation on nuclear matters 

remains important to NATO’s commitment, reiterated in the alliance’s 

2012 Deterrence and Defense Posture Review, that “[a]s long as nuclear 

weapons exist, NATO will remain a nuclear alliance.”231

Missile Defenses. The Obama administration believes missile 

defenses are critical to U.S. assurance strategies, as evidenced by 

increasing requests by allies and partners for coverage by these 

systems.232 Missile defenses are particularly important for assuring allies 

and partners living in the shadow of regional adversaries armed with 

ballistic missiles that are known or suspected of carrying WMD.233 By 

providing a shield against ballistic missile strikes, they assure allies that 

their population centers and key assets are not defenseless against these 

types of attacks. Furthermore, missile defenses can also address allied 

concerns regarding the potential vulnerability of U.S. forces deployed on 

behalf of their defense, providing a capability that can counter an 

offensive system that represents the key offensive strike capability of a 

number of potential adversaries. As such, missile defenses can ensure the 

United States remains an ally’s primary “security guarantor,” 

strengthening the two states’ defense relationship and ensuring the latter 

does not pursue capabilities such as nuclear weapons.234

Current Issues and Challenges for U.S. Extended Deterrence and 

Assurance Strategies

As discussed in Part 4, geopolitical change, a constantly shifting 

threat environment, and the critical role played by the United States in 

allied regional and national defense strategies are all factors contributing 

to the need to continually address questions from allies, regarding U.S. 

extended deterrence and assurance strategies. Our survey of these 
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strategies from 1945-2008 found that many of these questions and 

challenges fell into four general categories: 1) doubts about the strength 

of U.S. political resolve; 2) questions about the sufficiency of U.S. 

military capabilities; 3) the challenge of meeting the differing 

requirements of extended deterrence and assurance within a region or for 

a particular set of adversaries and allies, and; 4) the general opposition of 

allies to changing existing strategies, plans, and assigned forces.

During its first term, the Obama administration re-affirmed many 

of the central tenets guiding U.S. extended deterrence and assurance 

policies and strategies. The administration sought to continue the 

traditional U.S. role of “security guarantor” for allied states across the 

globe, reiterated the U.S. commitment to longstanding alliances and 

defense relationships, and stated its strong support for maintaining the 

U.S. nuclear umbrella over its friends abroad. In doing so, the Obama 

administration, similar to its predecessors, has sought to address 

fundamental questions from foreign actors – both allied and adversary –

about U.S. extended deterrence and assurance strategies (such as “will 

the United States risk suffering a nuclear attack on its homeland in order 

to defend an ally from foreign aggression?”) that have endured over time. 

However, the administration also sought to break with the 

national security policies of its predecessor and overhaul U.S. strategies 

it judged as out of date and unable to address contemporary security 

challenges. In addition, it believed the United States faced an urgent 

need to revitalize and re-tool its defense relationships with allies and 

partners abroad. In response, it attempted to expand communication and 

cooperation with friendly states in order to better address their defense 

and deterrence requirements and make more efficient use of U.S. 

resources. As with preceding administrations that have advocated or 

implemented changes to earlier U.S. strategies, this has raised questions

and concerns in some foreign capitals. 

In addition, the Obama administration, as with other post-Cold 

War presidencies, has also faced a shifting threat environment that 

presents new or evolving challenges to U.S. extended deterrence and 

assurance strategies. 

All of the above factors – enduring challenges intrinsic to the 

extension of deterrence and the provision of assurance, foreign actors’ 

questions about adapted U.S. strategies, and the emergence of new and 

evolved threats – raise important issues and questions for U.S. extended 

deterrence and assurance strategies. The next section will address 

general issues and questions; Part 6 will addresses issues and questions 

specific to different geographical regions (East Asia, NATO/Europe, and 

the Middle East).
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The Broad Requirement of 21st Century Deterrence

The Obama administration’s assessment of 21st century threats to 

the security of the United States and its allies identifies a broad range of 

actors and actions that the U.S. government and military must deter. 

This broad concept of deterrence reflects the geopolitics of the 

post-9/11 era, where the United States and its allies are confronted with 

security challenges posed by a number of direct and potential 

adversaries, to include strategic competitors, risk-taking regional powers, 

and transnational terror networks. It is also a response to scientific and 

technological developments that have extended the reach of the tools of 

state power, lowered the threshold for non-state actors to develop 

capabilities that can significantly harm the United States or its allies, and 

opened domains such as space and cyber space to new forms of 

competition and conflict. 

This has led the Obama administration to describe the 

requirements of deterrence and extended deterrence as encompassing 

strategies, forces, and operations developed to forestall attacks against 

the United States and its allies across all five strategic domains – land, 

sea, air, space, and cyber space. In addition, the Obama administration 

also believes the United States must develop strategies for deterring 

efforts to restrict the freedom of movement within, use of, or access to 

those areas or aspects of these domains that are part of the “global 

commons” (for example, international waters or international airspace). 

The United States has long sought to develop strategies to deter 

foreign actors from undertaking actions that harm its homeland, national 

interests, or its allies. The Obama administration’s depiction of the depth 

and breadth of deterrence and extended deterrence requirements, 

however, expands upon its predecessors in ways that raise a number of 

potential issues.

Will the United States have enough resources and capabilities to 

address the broad requirements of 21st century deterrence? The 

requirements articulated above – protecting the United States and 

multiple allies (NATO alone includes 27 other states) with deterrence 

strategies across five domains and against a range of potential 

adversaries – suggest the U.S. military must simultaneously conduct 

multi-dimensional deterrence operations utilizing all of the tools of 

modern military force while also accounting for the unique demands of 

each individual adversary. On the other side of the deterrence-assurance 

equation, this also requires the development of assurance strategies 

addressing allied security needs in all five strategic domains. 
105

Implementing these strategies requires significant military 

capabilities allowing the United States to rapidly and decisively project 

power in land, sea, air, space, and cyber space environments. The 

“rebalancing” of the U.S. military and the requirements of an austere 

budget environment, however, have led the United States to prioritize 

some military capabilities over others, geographically shift its strategic 

attention, and make cuts across all the armed services. 

This may raise questions for adversaries and allies regarding 

whether the United States can implement strategies and plans meeting 

the demanding requirements of 21st century deterrence, extended 

deterrence, and assurance. With the U.S. defense budget either likely to 

remain flat or face additional cuts in the near term, some U.S. military 

capabilities used within current extended deterrence and assurance 

strategies may be unavailable or downgraded in the future.235 Moreover, 

some capabilities currently under development for future roles in defense 

and deterrence strategies may not progress beyond the research and 

design phase due to funding issues. The 2012 DSG’s discussion of a 

“rebalance” toward the Asia-Pacific also led some U.S. allies outside this 

region to question whether the United States could focus policy attention, 

and sufficient military capabilities, on maintaining seamless deterrence 

strategies against their potential adversaries. 

The United States will also have to exercise caution as it applies 

this framework of extending deterrence across multiple domains to 

specific defense agreements. U.S. allies closely watch Washington’s 

interactions with other allies, and may be sensitive to indications that 

they are not afforded the same type of protection as another state. The 

inclusion of cyber space and cyber activities into U.S. defense guarantees 

for Australia, for example, and U.S. support for the development of a 

Cyber Defence Centre for NATO, may lead to future requests from other 

U.S. allies for the same “cyber umbrella” extended to these states.236 

Few strategists are likely to deny that the United States needs to 

exercise deterrence across all five strategic domains. If resource 

constraints continue into the future, however, the United States may find 

it difficult to maintain a high level of deterrence across all five, 

ultimately forcing it to prioritize certain domains (and associated 

deterrence strategies) over others. This may represent an enduring 

challenge for U.S. leaders if threats continue to proliferate while defense 

resources remain static or decline. In addition, a mismatch - or the 

perception that one may exist – between the United States’ description of 

deterrence requirements and the resources it makes available to its 

military forces will seriously complicate future U.S. assurance strategies. 

With many U.S. allies remaining heavily dependent on the U.S. defense 
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umbrella over their countries for their security, any indication this 

umbrella may spring a leak will raise serious concerns in allied capitals. 

Will foreign parties speculate the United States is a vulnerable 

superpower? The United States may face challenges meeting the broad 

requirements of 21st century deterrence and extended deterrence if its 

adversaries – or allies – calculate the United States is unable or unwilling 

to meet them all. In order to continue to convince potential U.S. and 

allied adversaries that it is both willing and able to impose unacceptable 

costs on them in response to a potential attack on the United States or its

friends abroad, it may need to address a number of issues regarding 

current and future potential resource constraints and vulnerabilities. 

First, the defense guidance documents of the Obama 

administration emphasize the importance of developing “flexible” and 

“mobile” military forces that allow the United States to nimbly and 

efficiently flow military assets – particularly advanced, expensive 

capabilities such as missile defenses – to areas where they are needed.237

These types of capabilities permit the United States to quickly and 

effectively shift forces and implement strategies in reaction to particular 

crises. 

In an era of rebalancing and austerity, however, this concept of 

flexibility may conflict with the concept of closely tailoring extended 

deterrence and assurance strategies. Each tailored strategy, for example, 

may call for the employment of a particular force profile; as such, it may 

not be possible to simultaneously employ several at the same time if they 

require relatively scarce resources such as missile defense batteries or 

tactical nuclear-capable delivery systems. In short, even highly-flexible 

forces may be stretched to the breaking point within an environment 

where multiple demands – whether across domains, across geographic 

regions, or both – must be met. 

Second, the U.S. strategic policy community has openly 

discussed the significant challenges currently faced by the United States 

in outer space and cyber space, to include frank public assessments of the 

U.S. government and military’s growing but limited ability to deter and 

combat cyber espionage and cyber-attacks. As General Keith B. 

Alexander, Commander of U.S. Cyber Command, stated in March 2013 

testimony to Congress,

We have some confidence in our ability to deter major 

state-on-state attacks in cyber space but we are not 

deterring the seemingly low-level harassment of private 

and public sites, property, and data .... Dynamic 

defenses have brought about noticeable improvements in 
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the overall security of DoD information environment. 

We know for a fact that our adversaries have to work 

harder to find ways into our sensitive but unclassified 

networks. Unfortunately, adversaries are willing to 

expend that effort, and DoD’s architecture in its present 

state is not defensible over the long run.238

As such, adversaries or allies may conclude that, at present, the United 

States cannot fully protect core assets, or extend deterrence, across two 

critical strategic domains. 

Third, despite ongoing U.S. government efforts to combat the 

proliferation of WMD and their potential delivery systems, and a number 

of notable successes in the post-Cold War era, countries such as the 

DPRK, Iran, and Syria have developed, acquired, or continue to pursue 

both. These potential adversaries, as well as major powers such as 

Russia and China, can hold – or believe they can hold, which is also 

significant for the purposes of deterrence – U.S. troops and allies abroad 

at risk with WMD capabilities. In addition, with the DPRK continuing to 

invest in long-range missiles, Pyongyang either believes it can hold the 

U.S. homeland at risk with a nascent ICBM or hopes to convince others 

this is the case (publicizing photographs, for example, showing missile 

flight paths for potential strikes on CONUS targets).239

In short, while the United States possesses offensive and 

defensive capabilities to address these challenges, it is possible that 

adversaries or allies would conclude there are significant gaps within the 

U.S. armor. Regardless of whether these perceptions are empirically 

true, they represent a challenge to the U.S. ability to deter and extend 

deterrence. With deterrence in the eye of the beholder, it is important for 

the United States to project an image of strength to both adversaries and 

allies, particularly in areas or operations that U.S. leaders have identified 

as important to U.S. and allied security. If the United States continues to 

struggle to address new space and cyber threats, and if potential 

adversaries continue to develop new, more sophisticated, and more 

diverse WMD and long-range strike capabilities, the United States may 

face increasingly persistent questions from foreign actors regarding 

whether it can continue to meet global defense obligations and carry out 

round-the-clock, cross-domain strategic operations.

Can the United States effectively coordinate its military 

capabilities in order to develop and implement effective deterrence 

strategies and operations across the globe and across all five domains? 

The broad requirements of contemporary deterrence and extended 

deterrence suggest the need to develop extremely close coordination 
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between U.S. military geographic and functional combatant commands 

in order to develop strategies and conduct operations against 

contemporary adversaries. In addition, the effective development, 

communication, and implementation of these strategies often requires a 

“whole of government” approach including diplomats, intelligence 

analysts, and other government officials. As identified by the 2012 Joint 

Operational Access Concept (JOAC) this places new demands upon the 

U.S. military:

Attaining cross-domain synergy to overcome future 

access challenges will require a greater degree of 

integration than ever before. Additionally this 

integration will have to occur at lower echelons....

240

Each additional actor involved and each additional domain 

factored into strategy and planning increases the degree of difficulty in 

executing operations. Moreover, while the U.S. military has long 

worked to minimize friction in joint operations, some U.S. national 

security experts have registered concerns the United States government 

lacks a clear framework for cross-domain deterrence, and as such may 

struggle to communicate or execute deterrence strategies against 

potential adversaries (particularly in areas such as space and cyber 

space).241 The 2012 JOAC, however, concludes that realizing crossdomain synergy across the U.S. military is an ongoing process that will 

take time and resources, and may be difficult to maintain in times of 

crisis or combat.242 The same conclusion also applies to coordinating 

deterrence strategies and operations across the U.S. government or in 

cooperation with allies. 

In short, the concepts, strategies, and procedures for deterring 

adversaries across all five strategic domains remain works in progress. 

Similar to the early years of the atomic age, when thinkers and strategists 

sought to either adapt ideas about defense and deterrence to the new 

strategic era or invent new ones, current efforts to address present 

deterrence challenges are likely to evolve over time. Both policymakers 

and planners will need to be flexible and innovative in order to facilitate 

coordination that are either new, re-engineered to add additional 

domains, or overhauled to respond to geopolitical change.

What is the threshold for deterring adversary actions within the 

global commons? The Obama administration has identified a 

requirement for the United States to deter adversaries from interfering 

with, or otherwise destabilizing, the global commons (“domains or areas 

that no one state controls but on which all rely”).243 Other guidance 

documents have identified a specific requirement to deter adversary 
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A2/AD actions in areas or aspects of the global commons across all five 

strategic domains.244

Establishing and communicating clear thresholds for U.S. 

deterrence strategies regarding the broad range of actions that disrupt or 

degrade the global commons, however, presents difficult questions. The 

United States, for example, has taken direct steps in the past to deter 

A2/AD actions with regard to key international waterways. To date, 

however, it has largely restricted itself to diplomatic protests in response 

to actions degrading the space environment – such as “dazzling” attacks 

on U.S. satellites or anti-satellite weapons tests creating debris 

endangering the systems of all space-faring states. As U.S. and allied 

reliance on the global commons increases into the future, the United 

States will likely need to continually re-assess the level and types of 

adversary actions that it seeks to deter, while also carefully considering 

what resources are available to enforce the “red lines” it chooses to 

establish. 

Tailoring Assurance and Extended Deterrence 

The current U.S. view of extended deterrence and allied 

assurance emphasizes the importance of specifically tailoring these 

strategies to reflect the unique dynamics and capabilities of allies, 

partners, and their potential adversaries. It also views tailoring extended 

deterrence and assurance strategies as important for addressing specific 

regional challenges and for ensuring the best use of finite defense 

resources. In addition, it envisions tailoring as a truly collaborative 

process, with the United States and allies and partners working together 

to integrate their specific military capabilities and make use of their 

access to information and intelligence that U.S. forces may not possess.

 

What happens if/when the United States’ turns down specific 

allied requests? The Obama administration has worked to develop better 

mechanisms and/or processes for communication with U.S. allies on 

deterrence issues. U.S. allies, for example, were appreciative of the 

Obama administration’s decision to involve them in a range of 

discussions on nuclear issues prior to the publication of the 2010 NPR; 

previous U.S. reviews did not include close consultations with other 

states. In many cases, improved dialogue will likely improve the ability 

of the United States to assure its allies, providing a forum for U.S. 

leaders and officials to address allied questions and concerns regarding 

deterrence matters. Mechanisms such as the U.S.-ROK EDPC can also 

facilitate allied communication of information and insights on topics 
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(adversary decision-making process, for example) improving the design 

and implementation of deterrence strategies. 

As demonstrated by the “Healy Theorem,” however, the 

requirements of extended deterrence and allied assurance often differ, as 

do U.S. and allied assessments of the relative capabilities required to 

deter the latter’s adversaries. The development of channels expressly 

devoted to extended deterrence and assurance discussions may place the 

United States in the uncomfortable position of having to tell an ally that 

its assumptions on U.S. deterrence strategies or capabilities are wrong, or

that the United States cannot accommodate a specific request regarding 

its defense. For example, an ally facing an adversary suspected of 

illicitly developing nuclear weapons may ask the United States to deploy 

nuclear-capable forces to its territory in order to demonstrate that it is 

directly under the U.S. nuclear umbrella; a number of diplomatic or 

military reasons (a lack of adequate facilities for nuclear-capable 

delivery systems and/or nuclear warheads, for example), however, may 

lead the United States to turn down this request, causing a serious rift 

between the two states.245 Such a rift may occur regardless of whether a 

deterrence dialogue mechanism exists between the United States and an 

ally; where these mechanisms exist or are created, however, U.S. leaders 

will need to take extra care in managing allied expectations regarding the 

scope of the protection afforded to them.

Can the United States successfully tailor strategies for opaque 

adversaries? The concept of tailoring deterrence and extended 

deterrence strategies relies on the collection and analysis of a broad 

range of data – to include accurately assessing an adversary’s belief 

system and the impact of core ideals on its decision-making processes –

to design effective deterrence strategies and operations. Accurate 

information and intelligence, however, may be difficult to attain. Hard 

data on the deliberations and strategic calculations of DPRK leadership 

councils, for example, remains difficult to acquire.246 Moreover, 

different U.S. government analyses on the programs and policies of 

potential adversaries may reach differing conclusions based on the 

information at hand. These factors complicate efforts to closely tailor 

deterrence strategies for opaque or mercurial opponents. 

Increasing Allied Involvement in Deterrence and Defense Strategies 

The Obama administration has also sought to increase allied 

involvement in the development and implementation of deterrence and 

defense strategies, hoping to ease the defense burden on the United 
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States and asserting that closer deliberations and cooperation with 

friendly states directly contributes to their assurance. 

Can allies contribute more? In June 2011, Secretary of Defense 

Gates warned members of NATO that the alliance faced “irrelevance” if 

member states did not contribute more resources to defense 

capabilities.247 Gates’ comments reflected both an assessment of 

“NATO’s serious capability gaps and other institutional shortcomings 

laid bare by the Libya operation” – which, despite Libya’s proximity to 

the European members of the alliance, heavily relied on U.S. combat 

forces, logistical support, and other assets – and an ongoing trend, 

exacerbated by the global economic downturn, of NATO states 

repeatedly cutting their defense budgets. 

The military forces of a number of major U.S. allies in Europe, 

however, have faced additional cuts since Gates’ demarche. The UK 

Ministry of Defence, for example, had its budget slashed by 249 million 

GBP in 2013-14; the cuts forced the British Army to reduce its ranks by 

20,000 soldiers and disband several battalions.248 Germany also plans to 

cut 7.8 million Euros from its 2013 budget and has stated that it will seek 

additional reductions in future years.249 These significant cuts, and the 

low prospect of NATO states raising their defense spending in the near 

future, demonstrate that a number of key U.S. allies may lack the 

capabilities to take a greater role in deterrence strategies and operations.

Will the United States lose its ability to influence and advise 

allies when it has fewer forces and a lesser role in defense partnerships? 

The United States has traditionally represented the strongest member 

within alliances or defense partnerships, both in terms of decisionmaking authority and military force (particularly in regard to nuclear 

forces). However, as the United States reduces its military footprint 

abroad, encourages allies to develop or purchase their own advanced 

military capabilities, and asks allies to take a greater role in deterrence 

and defense planning, it may find itself in circumstances where an ally 

has the military forces and political resolve to take action without 

coordinating with U.S. military forces or their political leadership in 

Washington. 

Close cooperation with allies remains vital to the success of U.S. 

extended deterrence and assurance strategies, and it is in the best 

interests of the United States to encourage its allies to develop strong 

militaries (particularly in light of the budget challenges faced by many 

allies). There is a tension, however, between building up allies and 

retaining the political capital and military capabilities necessary to 
112

persuade them not to undertake unilateral actions that the United States 

does not support. As the United States advocates for allies to take a 

larger role in regional deterrence and defense matters, it may need to 

devote close attention to managing alliance relations in order to ensure 

friendly regimes do not make decisions that may complicate the United 

States’ ability to protect them in a crisis or conflict, or that may lead to 

broader regional instability, possibly placing the security of other U.S. 

allies at risk. 

Focusing Extended Deterrence Strategies on Risk Taking States

The Obama administration has focused its discussions of 

extended deterrence strategies on “risk taking” regimes such as Iran and 

the DPRK, and asserts that the deterrence by denial capability provided 

by missile defenses will play a critical role against actors that may not 

always be deterred by the threat of punishment. 

Does this change the focus, strategies, or capabilities applicable 

to deterring other actors? The United States’ present focus on states 

such as Iran and the DPRK may lead U.S. allies facing other potential 

threats to question whether the United States has changed its views or 

strategies on extending deterrence against other potential adversaries. 

Some U.S. allies, for example, view Russia and/or China as 

potential security threats. The Obama administration’s efforts to 

establish “strategic stability” with these states reflects the significant 

benefits to the United States and its allies of stable relations between 

major non-allied powers. Administration officials, however, have also 

suggested the United States and Russia could exchange the nuclear 

deterrence concept of “mutually assured destruction” for a broader 

diplomatic-military construct of “mutually assured stability.”250 The 

administration’s unclassified guidance documents, such as the 2010 NPR 

and 2013 RNES, state that given the size of Russia’s nuclear forces, and 

the ongoing modernization of Russian and Chinese nuclear arsenals, 

nuclear forces remain important to the stability of these bilateral security 

relationships. The latter also notes that a significant disparity between 

U.S. and Russian nuclear forces could raise concerns amongst allies 

(although unspecified, this statement appears to refer to strategic nuclear 

forces, as a significant disparity already exists between U.S. and Russian 

non-strategic nuclear forces).251 These and other discussions of strategic 

stability, however, give few details regarding U.S. extended deterrence 

and assurance strategies either for these specific states or, more 

generally, for how these strategies will address any state with a 

significant nuclear arsenal. While U.S. allies, in general, support 

improved relationships between Washington, Moscow, and Beijing, they 
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may also require reassurance that the United States remains fully 

resolved, and militarily prepared, to extend deterrence against these 

major conventional and nuclear powers. 

In addition, the Obama administration’s appeals to Russia and 

China to join the United States in de-emphasizing nuclear forces and 

nuclear deterrence within their geostrategic relationships have met with 

skepticism and opposition in both countries. Russia has remained 

adamant that nuclear forces are central to its defense strategy and 

necessary to offset the advanced conventional, space, and missile defense 

forces of other states.252 It has also rejected the idea that nuclear 

deterrence in the form of mutually assured destruction may no longer 

apply to the U.S.-Russia strategic relationship, and its military doctrine 

continues to identify NATO (and efforts to boost its capabilities or 

expand the alliance) as the primary “external threat” to its national 

security.253 In early 2013 China re-affirmed the critical deterrence role 

played by its nuclear forces vis-à-vis other nuclear states and suggested it 

might consider altering its stated “no first use” policy for nuclear 

weapons due to concerns about U.S. missile defense and “conventional 

strategic strike” capabilities.254 Russia and China remain convinced 

nuclear deterrence plays a central role in the geostrategic dynamics of 

21st century international affairs; moreover, both view nuclear weapons 

as an important counterweight to U.S. advantages in other types of 

military forces. 

These factors may complicate U.S. efforts to focus extended 

deterrence strategies on risk-taking states and reduce the role of nuclear 

forces, and nuclear deterrence, in its strategic relations with Moscow and 

Beijing. U.S. allies may also become nervous if they feel the world’s 

three foremost nuclear powers do not see eye-to-eye on questions of 

nuclear deterrence. The United States will need to balance diplomacy 

and deterrence imperatives within its multifaceted relationship with 

major powers while also maintaining ironclad deterrence strategies 

against risk taker states. This challenge will likely endure for the 

foreseeable future, particularly as long as nuclear forces remain 

important to the national security of multiple states.

How to Deter Risk Taking States? The Obama administration 

discusses missile defenses as an important deterrence by denial 

capability against risk taking states, based on an assessment that, in the 

absence of these defenses, these states might believe their possession of 

ballistic missiles could deter the United States from taking action against 

them, despite the U.S. military’s possession of superior strike 

capabilities. 
114

This is an assessment that presents deterrence as viewed through 

the lens of a potential adversary attempting to deter the United States. It 

suggests that deterrence by punishment strategies may not apply to risk 

taking actors equipped with ballistic missiles. While advancing missile 

defenses as a potential deterrence by denial response to this challenge, 

this assessment also raises questions regarding deterrence and these 

actors.

First, this assessment places much of the weight of responsibility 

for deterring these adversaries on missile defenses; deterring missile 

strikes will either succeed or fail depending on the adversary’s views of 

whether these systems are credible. What criteria will risk taker states 

employ to determine this form of credibility? One credibility challenge 

the United States and its allies must address is directly stated within the 

2010 BMDR: an order of magnitude (thousands of missiles versus 

hundreds of interceptors) separates the numbers potential attacking 

forces of adversaries from the numbers of defensive forces available the 

United States and its allies.255 The United States, for example, has 

developed the Theater High Altitude Air Defense system as a “globally 

transportable, rapidly deployable” asset critical to defending U.S. troops 

and allies abroad from ballistic missile strikes; as of late 2012, however, 

it had only activated three batteries (each battery includes a small 

number of launchers, with each launcher capable of carrying eight 

interceptors).256 

Second, if deterrence by punishment strategies are of uncertain 

value with regard to these states, and deterrence by denial strategies (in 

the form of missile defenses) must be employed against their ballistic 

missile capabilities, are other forms of deterrence by denial besides 

missile defenses necessary to address the other capabilities at their 

disposal? The DPRK and Iran have demonstrated a willingness to 

employ various forms of asymmetric warfare against the United States 

and its allies. The DPRK, for example, has increasingly employed 

cyber-attacks against South Korean civilian targets such as banks and 

news organizations, and Iran continues to threaten to use A2/AD attacks 

to slow or halt shipping in the Persian Gulf.257 

U.S. and allied missile defenses, if considered credible by risk 

taker adversaries, may lead those states to elect against using ballistic 

missiles to coerce or attack the United States and its friends abroad. This 

suggests the United States will need to develop other deterrence by 

denial capabilities and strategies to deter (and extend deterrence) against 

risk taking states. 

The 2010 BMDR’s brief discussion of missile defenses and 

deterrence raises the above issues and alludes to other challenges 
115

stemming from the broader question of how to calibrate deterrence by 

punishment and deterrence by denial strategies (and the resources 

necessary for their implementation) to counter actors willing to accept 

significant risk in order to threaten (and/or attack) the United States and 

its allies. The approach of tailored deterrence suggests the answer is 

likely nuanced and may require frequent review and reappraisal. 

Adversaries willing to take big gambles pose serious challenges to the 

development of extended deterrence and assurance strategies; advanced 

capabilities such as missile defenses are likely necessary, but not 

sufficient, for addressing this challenge in the 21st century.

 

Can Missile Defenses Deter Missile Development and 

Acquisition? The Obama administration’s 2010 BMDR suggests missile 

defenses represent a key deterrence by denial capability both on the 

battlefield and within regional geopolitical rivalries. It asserts that when 

these defenses are effective and deployed in strength, they can deter an 

adversary from launching missiles in conflicts or crises. Moreover, over 

the long term, they argue an airtight missile defense shield can dissuade

adversaries from using resources to develop or acquire ballistic 

missiles.258

In the near-term, however, available evidence indicates that 

contemporary U.S. and allied missile defenses do not appear to have 

affected the calculus of these potential adversaries in regards to 

developing, testing, or fielding ballistic missiles. Despite ongoing U.S. 

government efforts to improve U.S. and allied missile defenses in 

Europe, the Middle East, and East Asia, in the years after the publication 

of the 2010 BMDR Iran and the DPRK continued to devote extensive 

resources to expanding their current missile fleets and developing longerrange missile platforms (including space launch vehicles). 

The U.S. intelligence community, for example, reported in April 

2013 that it assessed the DPRK as having taken “initial steps” toward 

fielding a new road-mobile ICBM.259 The assessment followed shortly 

after the DPRK publicly stated the “reckless nuclear threat [of the United 

States] will be smashed by the ... cutting-edge smaller, lighter and 

diversified nuclear strike means of the DPRK.” Although it was not 

clear if this statement was referring to DPRK nuclear-capable delivery 

systems and/or nuclear warheads (or it may have simply represented 

bellicose propaganda attempting to inflate the country’s capabilities), the 

statement and U.S. intelligence assessment both reflect Pyongyang’s 

determination to pursue additional missile capabilities despite 

international economic sanctions and U.S. efforts to develop cooperative, 
116

theater, and national missile defenses geared to address the DPRK 

missile threat.260

Reducing Reliance on Nuclear Forces and Increasing the Role of 

Missile Defenses

Current guidance from the Obama administration states that 

nuclear forces, while critical to extended deterrence and assurance 

strategies, will play a decreased role in relation to the conventional and 

missile defense forces that are also assigned to these missions. In 

addition, the number and variety of U.S. nuclear forces continued to 

slowly decline during President Obama’s tenure as a result of policy 

decisions, the ratification and initial implementation of the U.S-Russian 

Federation New START Treaty, and the retirement or dismantlement of 

a number of delivery systems and warheads.

How “Reduced” is the Role of Nuclear Forces in U.S. Defense 

Strategy, and What are the Implications for the U.S. Nuclear Umbrella?

The reduced role for, and reliance upon, U.S. nuclear forces in deterrence 

strategies will place responsibilities on conventional and missile defense 

forces. The Obama administration has clearly signaled that it believes 

Cold War deterrence by (nuclear) punishment models are poorly suited 

for deterring contemporary adversaries such as risk-taking states. On 

conceptual and operational levels, however, a shift in responsibilities 

between these three types of forces appears to remain a work in progress. 

Nuclear, conventional, and missile defense forces each bring broadly 

differing capabilities to any military strategy or operation, and one type 

often cannot directly substitute for the effects provided by another. 

Furthermore, adversaries are likely to view each type as posing a 

different type of challenge to their own policies, plans, and operations. 

As such, how, when, where, and why nuclear, conventional, and/or 

missile defenses affect the deterrence calculations of potential 

adversaries will likely differ. The implications these factors carry for 

U.S. extended deterrence strategies de-emphasizing nuclear forces 

remain unclear. If missile defenses address the threat posed by ballistic 

missile strikes (a role played in the past by nuclear forces, albeit using a 

different form of deterrence to prevent an adversary from launching this 

type of strike) what offensive conventional forces will take a more 

prominent role in holding key adversary assets at risk?

The implications of the relative reduction of the role of nuclear 

forces in relation to conventional and missile defense forces also remain 

uncertain to many U.S. allies and partners. While welcoming U.S. 

efforts to promote nuclear nonproliferation objectives by signaling a 
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willingness to decrease the overall role of nuclear forces in defense 

planning, they question whether other types of forces can adequately fill 

whatever roles are vacated by nuclear weapons and delivery systems. 

Many U.S. allies are convinced, for example, that nuclear 

weapons remain essential to deterring nuclear-armed adversaries. For 

allies facing direct nuclear threats, the United States may need to directly 

address concerns that the U.S. force mix for countering nuclear and 

WMD-armed adversaries has de-emphasized nuclear forces to a degree 

that Washington can no longer provide for their defense. Indeed, some 

experts and politicians in allied states are publicly stating that further 

U.S. nuclear reductions will place the future credibility of U.S. nuclear 

guarantees in doubt. For example, Cheon Seongwhun, a Senior Research 

Fellow at the Korea Institute for National Unification (a think tank 

funded by the ROK government) has argued the Obama administration’s 

“decisions to reduce the role of nuclear weapons...will inevitably have 

the effect of shrinking the nuclear umbrella the United States provides to 

its allies.” In response, he has called for the United States to improve its 

ability to assure Seoul by developing a “Korean Peninsula Tailored 

Deterrence Architecture” that includes the deployment of U.S. tactical 

nuclear weapons to U.S. bases in the ROK, arguing that:

considering the uniqueness of security threat faced by 

South Korea...there is no other place in the world except 

South Korea that deserves first-hand access to the U.S. 

extended nuclear deterrence.261

Some Japanese policy experts have also registered concerns regarding 

whether U.S. nuclear reductions – in particular, the retirement of the 

TLAM-N - signaled a slackening of the U.S. commitment to nuclear 

extended deterrence in the Asia-Pacific region. As noted by Ken Jimbo, 

a Japanese scholar and frequent commentator on nuclear issues, Japan 

would never request the deployment of U.S. nuclear weapons on its 

territory, but strongly supports U.S. extended deterrence strategies that 

visibly deploy nuclear-capable aircraft in the Asia Pacific.

[T]here was a certain amount of concern in the Japanese 

policy community that the retirement [of the TLAM-N] 

symbolizes the reducing visibility of U.S. nuclear 

commitments in Asia .... I think that ensuring the 

visibility of the U.S. nuclear commitment in Asia by 

flexibly forward deploying the air-component will 

become highly important in post-NPR extended 

deterrence in Asia.262
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Some conservative political figures in the ROK and Japan have 

also called for the United States to either bolster its nuclear security 

guarantees to their country or for the development of national nuclear 

weapons programs. Former ROK legislator and presidential candidate 

M.J. Chung stated in an address to the 2013 Carnegie Endowment 

Nuclear Policy Conference that the “failure” of international 

nonproliferation efforts, and the renewed importance of strengthening 

nuclear deterrence strategies in response to the DPRK’s development of 

nuclear weapons and delivery systems, led him to call for the United 

States to either deploy nuclear forces on the peninsula or the ROK to 

pursue its own independent nuclear deterrent.263 In Japan, former finance 

minister Shoichi Nakagawa, former defense minister Shigeru Ishiba, and 

former Prime Minister Shinzo Abe have all voiced support for Japan 

considering whether to develop its own nuclear weapons program. In 

addition, the country’s largest newspaper noted in an op-ed defending the 

country’s use of civilian nuclear power in the wake of the Fukushima 

crisis that the country’s civilian plutonium stores “works diplomatically 

as a nuclear deterrent.”264 These direct discussions of the potential value 

of a future Japanese nuclear weapons program signal a significant shift in 

the country’s political discourse, which long focused entirely on public 

support for comprehensive nuclear disarmament. 

In addition to calls from some policy experts and politicians in 

allied countries to reevaluate the U.S. nuclear umbrella and weigh the 

merits of national nuclear weapons programs, publics in the allied states 

such as ROK and Turkey are also voicing support for the potential future 

development of an independent nuclear deterrent. A public opinion poll 

conducted by the Asan Institute, a privately-funded think tank in Seoul, 

in early 2013 (shortly after North Korea’s third nuclear test) found 66 

percent of respondents – with little significant deviation based on 

political affiliation – supported starting an ROK nuclear weapons 

program.265 A March 2012 poll conducted by Centre for Economics and 

Foreign Policy Studies, an independent think tank in Istanbul, found that 

54 percent of respondents supported Turkish development of a nuclear 

weapon in response to a potential future Iranian nuclear capability.266

The above policy, political, and public opinion developments do 

not necessarily indicate that these countries will begin independent 

nuclear weapons programs in the near future. They are significant,

however, in revealing that a number of developments during the postCold War era have led U.S. allies to openly debate the value of fielding 

national nuclear weapons assets in order to guarantee their security 

against WMD-armed adversaries. Public figures and average citizens in 

these countries – all close U.S. allies – no longer consider it taboo to 
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discuss a course of action that would directly violate the Nuclear NonProliferation Treaty, strain or break ties with the United States and other 

allies, and possibly lead to economic sanctions or isolation from other 

states in the international community. The experts, commentators, and 

publics discussed above, when considering the threat posed by current or 

future potential nuclear-armed adversaries, conclude that a nuclear 

deterrent – whether provided by the United States, or, if necessary, by 

their own militaries – is essential to their national security. Moreover, 

whether openly stated or implied, these parties may doubt the long-term 

effectiveness of the U.S. nuclear umbrella as a guarantor of their security 

within a multi-nuclear state geopolitical environment.267 Whether 

concerned U.S. forces may be insufficient to address future threats, or 

worried U.S. policymakers lack the political resolve to counter their 

regional adversaries, allied commentators and publics appear 

increasingly open to considering developing or maintaining some form 

of nuclear hedge (even if only in the form of fissile material stocks) 

against future uncertainty. 

In summary, a number of U.S. allies remain deeply skeptical of 

the concept that the value of nuclear weapons decreased relative to other 

types of military force in terms of their geopolitical importance or the 

deterrence value they provide. Indeed, some parties within the United 

States’ non-nuclear allies may believe nuclear weapons are becoming 

more salient to their national security. As a result, while some U.S. allies 

remain strongly supportive of additional arms control treaties and nuclear 

force reductions, other friendly states are concerned the U.S. nuclear 

arsenal may be nearing a “tipping point” whereby further reductions will 

impede Washington’s ability to extend deterrence to its allies. The 

United States will need to diligently address these types of concerns in 

order to address any future doubts about the capabilities or political 

resolve associated with the U.S. nuclear umbrella. A strong response to 

these concerns – which, whether they directly state it or not, question the 

credibility of U.S. extended deterrence and assurance strategies and echo 

the doubts about U.S. resolve articulated by President de Gaulle during 

the Cold War – is important to both ensure these relationships remain 

strong and prevent friendly regimes from considering whether to embark 

down the expensive, dangerous, and destabilizing path of nuclear 

proliferation. 

Can U.S. nuclear-capable aircraft carry the full weight of visible 

extended deterrence and assurance strategies and operations? The 

retirement of the Navy’s TLAM-N leaves the U.S. nuclear arsenal with 

one type of visible strategic nuclear delivery system (B-2 and B-52 long-
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range bombers) and one type of visible, forward-deployable tactical 

nuclear delivery system (F-15E and F-16 DCA). 

These aircraft, however, face a number of issues that may impact 

the credibility of these systems and, in turn, affect the credibility of U.S. 

extended deterrence and assurance guarantees. First, the aircraft are 

aging. The Air Force’s initial operating capabilities dates for its nuclearcapable aircraft are as follows: 1952 (B-52), 1979 (F-16), 1989 (F-15E), 

and 1997 (B-2). 

Second, there are a number of issues with the aircraft intended to 

take their place within the nuclear arsenal. Current U.S. DCA are slated 

for replacement by a nuclear-capable variant of the F-35, but problems 

with this type of aircraft have delayed its integration into the force and 

may complicate handoff of the extended deterrence/assurance mission. 

The F-35s problems may also raise issues for the future of NATO 

nuclear-sharing arrangements. Some U.S. allies intending to buy the F35 are becoming increasingly concerned about the aircraft’s development 

problems and rising price tag; others, such as Germany, have already 

decided to retire their DCA without replacement.268 In addition, the U.S. 

Air Force’s future long-range strike bomber (LRS-B) is, at present, a 

paper concept. Defense contractor proposals for the airframe are 

currently under consideration, but it will take years of research, design, 

development, and testing before the selected airframe selected is 

deployed, likely within the 2020s.269 

Third, the B-2, F-15, and F-16 all rely on the B61 gravity bomb 

for the purposes of nuclear extended deterrence operations. The B61 is

undergoing a life extension program (LEP); however, the program has 

encountered a number of problems and delays, leading the Government 

Accounting Office to raise questions about the U.S. ability to seamlessly 

maintain operational capabilities for NATO nuclear-sharing missions.270 

In addition, significant increases to projected costs of the LEP have led 

some members of Congress to criticize the National Nuclear Security 

Administration’s management of the process and question its ability to 

successfully overhaul the B61 or other nuclear weapons.271

With these aircraft and the B61 critical to U.S. extended 

deterrence and assurance strategies, the United States will need to 

resolve these issues in order to maintain the future credibility of its 

nuclear umbrella. 
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PART 6: REGIONAL ISSUES

Regional Security Architectures

A key aspect of the current U.S. approach to extended deterrence 

and assurance is focused on building, bolstering, and sustaining regional 

security architectures that will allow for the seamless development of 

joint defense plans and operations with allies and partners. This will 

improve the latter’s ability to defend themselves, and ease the ability of 

the United States to flow conventional, nuclear, and missile defense 

forces to a region in response to sudden crises or conflicts. 

This section provides an overview of current unclassified U.S. 

government guidance on extended deterrence and assurance policies and 

strategies for three regions where the United States has vital strategic 

interests and longstanding defense relationships: East Asia, the Middle 

East, and Europe. For each region, this presentation of current guidance 

is followed by a discussion of key issues for consideration during the 

development of future tailored extended deterrence and assurance 

strategies.

Efforts to create a more permanent, cohesive, and interoperable 

regional security architecture in East Asia and the Middle East as robust 

as the arrangements in Europe, however, face a number of significant 

obstacles.

East Asia

Extended Deterrence

In the Asia-Pacific theater, the DPRK is the primary focus of 

current U.S. extended deterrence policies and strategies. In the past, the 

United States has also extended deterrence against China and Russia. 

However, the United States now seeks to establish a relationship of 

“strategic stability” with these countries, a status that appears to 

incorporate elements of extended deterrence, diplomatic dialogue, and 

security cooperation.272

The United States’ 2012 “rebalance” (or “pivot”) to the AsiaPacific will likely have significant long-term implications for U.S. 

extended deterrence and assurance strategies across the region. At a 

minimum, it will refocus attention on how these strategies can help the 

United States shape regional dynamics to ensure its allies, partners, and 

interests are protected and the Asia-Pacific remains stable, peaceful, and 

open to international trade and transit. Rebalancing, however, may have 

deeper implications for extended deterrence and assurance in regard to 
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the critical – but limited – assets that play a vital role in these strategies. 

A nuclear arsenal declining in numbers and a missile defense architecture 

short of interceptors in the face of current and future threats may impose 

hard choices on planners whose task of rebalancing will necessarily 

reduce – perhaps significantly so – the resources available to other 

theaters and commands.

North Korea. From the negotiation of the armistice of the 

Korean War to the present day, the United States has maintained 

significant forces on the Korean Peninsula to deter an invasion of the 

ROK. The 2010 QDR states that the U.S. military “will develop a more 

adaptive and flexible U.S. and combined force posture on the Korean 

Peninsula to strengthen the alliance’s deterrent and defense 

capabilities.”273 Although the full implications of a more “flexible” U.S. 

military presence on the peninsula remain under development, the United 

States may seek in the long-term to switch out of some of the ground 

forces currently stationed in Korea with more mobile assets, as well as 

specialized forces such as missile defense units. This reflects a longterm trend of shifting the U.S. presence in Korea toward capabilities that 

can deter Pyongyang’s increased emphasis on ballistic missiles and away 

from forces deployed and postured to address an increasingly unlikely 

heavy ground assault across the Korean demilitarized zone. 

The DPRK’s aggressive development of nuclear weapons and a 

broad range of ballistic missiles, together with its leadership’s 

willingness to engage in risky, provocative acts (such as sinking the 

Cheonan in 2010 and testing of its third nuclear device in February 2013) 

have led the United States to conclude that deterrence-by-punishment 

strategies may be insufficient for preventing Pyongyang from continuing 

to harass the ROK.274 The United States views the deployment of robust 

missile defenses (both regional and national) as critical to extending 

deterrence against the DPRK, demonstrating to its leaders that it cannot 

prevent the United States from acting against it by threatening to use 

ballistic missiles against U.S. or allied targets.275

As part of the 1991 Presidential Nuclear Initiatives, the United 

States withdrew all non-strategic nuclear weapons deployed on the 

Korean Peninsula. The United States currently extends nuclear 

deterrence against the DPRK with a range of strategic nuclear forces and 

has the “capacity to redeploy” non-strategic nuclear systems to East Asia 

in a crisis, if needed.276 The most visible of these forces are the strategic 

long-range bombers rotating through the Asia-Pacific as part of the U.S. 

strategy of maintaining a “continuous presence” of nuclear-capable 

aircraft within the region. 
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China. The United States is currently engaged in a balancing act 

with China. The 2010 NPR, for example, states Washington’s interest in 

establishing a relationship of strategic stability with Beijing, while the 

2012 DSG’s pivot toward the Asia-Pacific is widely viewed in the region 

as focused on countering China’s increasingly capable and assertive 

military.277 

In one key respect, the United States has signaled that it does not 

intend to alter its deterrent relationship with China. The 2010 BMDR 

unequivocally states that U.S. national missile defenses are not designed 

for, nor intended to negate, China’s strategic nuclear forces.278 While not 

discussed in policy documents, this effort to separate missile defenses 

from the U.S.-China nuclear deterrence relationship may have important 

implications for U.S. regional extended deterrence. As noted above, 

however, China remains deeply skeptical of U.S. national missile defense 

plans, and has also objected to U.S. efforts to develop a regional missile 

defense architecture.279

The Obama administration, however, has also sought to reassert 

the United States as a Pacific power capable of balancing against any 

state seeking regional hegemony or otherwise taking actions to 

destabilize the Asia-Pacific. The United States has moved to establish 

defense ties with states such as Vietnam while also strengthening its 

defense cooperation with traditional allies such as Thailand, Australia, 

the Philippines, ROK, and Japan.280 The United States has also increased 

its regional force presence by recently concluding agreements to 

regularly rotate littoral combat ships through Singapore and U.S. 

Marines through Australia.281 While the U.S. government is taking care 

not to single out China as the reason for this increased force presence in 

the region, these moves boost the ability of the United States to extend 

deterrence against Beijing or any other regional actor that attempts to 

intimidate, coerce, or attack U.S. allies and partners in the Asia-Pacific.

The United States has also clearly communicated its 

determination to extend deterrence over vital international waterways 

and airspace in the Asia-Pacific on behalf of the principle of freedom of 

navigation throughout the region.282 Speaking at the Shangri-La 

conference, an annual Asia-Pacific security summit, Secretary of 

Defense Leon Panetta stated in June 2012 that:

Our approach to achieving the long-term goal in the 

Asia-Pacific is to stay firmly committed to a basic set of 

shared principles .... These rules include the principle of 

open and free commerce ... [and] open access by all to 

their shared domains of sea, air, space, and cyber 
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space....

283

The Panetta speech and other policies announced by U.S. senior 

officials have clearly communicated to all regional parties that the United 

States is mounting a determined defense of the right of all ships and 

aircraft – U.S., allied, and commercial, of all flags – to freedom of 

navigation through international waters and airspace.284 While unstated 

in official U.S. policy, within the Asia-Pacific this is widely interpreted 

as a U.S. response to recent Chinese efforts to claim sovereignty over 

important stretches of ocean and disputed minor islands, and recent 

related incidents where Chinese government ships in contested areas 

have threatened or harassed ships from other Asia-Pacific states.285

Russia. U.S. discussions of nuclear extended deterrence and 

Russia have typically focused on Europe. Russia, however, is also a 

major nuclear power in the Pacific and is seeking to upgrade its 

conventional force presence both within the region and across the Arctic. 

The Russian port of Vladivostok is home to the country’s Pacific fleet

which includes several nuclear submarines equipped with SLBMs. In 

recent years Russia has significantly increased its air patrols in the Arctic 

and on several occasions has flown nuclear-capable Tu-95 Bear bombers 

into Alaskan air-exclusion zones.286 While Western press reports and 

policy discussions featuring Pacific maritime disputes often focus on 

China, Russia and Japan also have a long-running and increasingly tense 

dispute over islands called the “Southern Kurils” by Moscow and 

“Northern Territories” by Japan.287 The inability of the two states to 

resolve their competing claims of sovereignty has prevented them from 

signing a peace agreement officially ending the Second World War. 

The 2010 NPR stated that the United States government will 

seek to establish a relationship of “strategic stability” with Russia. The

importance of this policy was emphasized by the appointment of former 

Undersecretary of State for Arms Control and International Security 

Affairs Ellen Tauscher as Special Envoy for Strategic Stability and 

Missile Defense in February 2012. Tauscher followed this appointment 

with several high-level meetings during 2012 on a range of topics related 

to strategic stability with Russian interlocutors. Although little progress 

was realized in resolving disagreements on issues such as missile 

defenses, the Obama administration remains committed to pursuing this 

form of stability with Moscow. From discussions of the U.S.-Russia 

security relationship within guidance documents such as the 2010 NPR 

and 2013 RNES, “strategic stability” appears to share a number of the 

characteristics of traditional understandings of nuclear deterrence.288 It is 

unclear, however, what implications the achievement of this state of 
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relations between Washington and Moscow might have for U.S. allies 

and partners in Europe or in the Pacific. 

Assurance

The United States has what is often described as a “hub and 

spoke” model of assurance in the Asia-Pacific, reflecting the existence of 

multiple, long-standing, official bilateral alliances (with ROK, Japan, 

Australia, the Philippines, and Thailand) but also the lack of a regionwide alliance structure akin to NATO in Europe. The long shadow of the 

Second World War complicates the relationship between Japan and a 

number of U.S. allies and partners in the region; in addition, a 

combination of differing cultures, divergent regional interests, and the 

tyranny of geography prevent the creation of a pan-Pacific U.S.-led 

defense coalition. 

Nevertheless, working with the United States to address common 

threats represents an important common denominator across the national 

security strategies of these disparate states. The 2012 DSG emphasizes 

the importance of the United States working closely with Asian-Pacific 

allies and partners to maintain peace and freedom of access across the 

region in order to ensure its “future stability and growth.” A joint 

approach is also presented as critical to “deter and defend” against the 

major threat to regional peace and stability posed by the DPRK and its 

nuclear weapons program.289

As a result, the United States has many friends in a region 

viewed as vital to U.S. and international security and prosperity. 

However, it also faces many complex diplomatic and defense challenges 

in its efforts to assure Asian-Pacific allies and partners with disparate –

and sometimes divergent – perspectives on national security 

requirements and the best approach for ensuing regional stability.

Japan. The United States is a close ally with Japan, with a 

defense relationship codified by the 1960 Treaty of Mutual Cooperation 

and Security between Japan and the United States of America. The 

treaty’s Article V states:

Each Party recognizes that an armed attack against either 

Party in the territories under the administration of Japan 

would be dangerous to its own peace and safety and 

declares that it would act to meet the common danger in 

accordance with its constitutional provisions and 

processes.290 

Japan faces a number of regional security challenges and turns to 

the United States for assurance as its most important ally. The country is 
126

the target of repeated threats from the DPRK, which has conducted 

recent ballistic missile tests through Japanese airspace and over its 

territory. Tokyo views DPRK as a significant, persistent threat to its 

security. 

Japan is also wary of China’s increasing regional influence and 

military strength. As with a number of other states, the legacy of the 

Second World War remains a stumbling block to cordial relations 

between the two states. The two countries also have a longstanding 

dispute over an island chain – called the Senkakus by Japan and Diaoyus 

by China – that escalated in late 2012, with Japan announcing plans to 

officially nationalize the territory and China responding with significant 

increases in patrols by government ships directly offshore from the 

disputed islands.291 

The United States assures Japan by stationing a significant 

conventional force presence within the country, including the U.S. Fifth 

Air Force at Yakota Air Base, the USS George Washington carrier group 

at Yokosuka, and both a significant U.S. Marine presence and Kadena 

Air Base in Okinawa. Official Japanese documents and statements often 

emphasize the importance of these U.S. forces to protecting their country 

from regional threats.292 With Japan facing increasing threats from 

growing regional ballistic missile arsenals, the United States also 

provides assurance to Tokyo through the two country’s close cooperation 

on missile defense programs. This cooperation includes joint research, 

testing, and exercises. Japan also hosts major system components for 

regional missile defenses, such as U.S. AN-TPY-2 radars.293 In addition, 

Japan relies on the United States for nuclear deterrence against regional 

nuclear threats. The U.S. government, whose recent retirement of the 

TLAM-N removed a non-strategic nuclear system that previously played 

a key role in Asia-Pacific regional deterrence, has pledged to Japan and 

other regional allies that they remain protected by a range of U.S. 

strategic and non-strategic nuclear delivery systems.294 The two 

governments also agreed in 2011 to establish the Extended Deterrence 

Dialogue as a bilateral extended deterrence consultative mechanism to 

address a range of matters, to include the U.S. “nuclear umbrella” over 

Japan.295

South Korea (ROK). The United States has maintained close 

defense ties with the ROK since the Korean War. The 1953 ROK-U.S. 

Mutual Defense Treaty pledges that any attack on either party will be 

met by a joint response to “meet the common danger.”296 The DPRK 

remains the focus of ROK defense planning, with the Korean Peninsula 

DMZ remaining heavily fortified by both sides and a potential flashpoint 
127

for future conflict. The DPRK repeatedly denounces the ROK 

government as a “puppet” regime and is committed to reunifying the 

country under Pyongyang’s rule.297 DPRK artillery and ballistic missiles 

continually hold a range of civilian and military targets at risk throughout 

the ROK. Despite the general deterioration of the country’s conventional 

military forces in recent years, DPRK artillery and missile batteries 

remain capable of heavily damaging Seoul and attacking a range of ROK 

and U.S. military targets within the initial phase of a potential armed 

conflict. The DPRK’s sinking of the ROKS Cheonan and shelling of the 

ROK’s Yeongpyeong Island in 2010 represented the most recent serious 

provocations by Pyongyang; the actions threatened the fragile peace 

between the two countries and led Seoul to re-evaluate the role of 

deterrence on the peninsula.298 While some ROK commentators have 

noted the rise of China with concern, the DPRK continues to dominate 

the country’s national security agenda.299

The United States provides assurance to the ROK through a 

variety of means. It maintains significant conventional forces within the 

country, which hosts approximately 28,500 U.S. troops, to include the 

Eighth Army in Seoul and the Seventh Air Force in Osan. The United 

States and the ROK are currently engaged in discussions regarding 

increasing their cooperation on missile defenses, with some media 

sources predicting that the Korean Ministry of Defense’s recently 

announced plans to upgrade its theater missile defenses will feature U.S.-

built PAC-3 Patriot missiles.

300 With the ROK now also facing a direct 

nuclear threat from the DPRK, it relies on the United States and its 

nuclear deterrent for protection.301 During the Cold War, the ROK 

hosted a large number of U.S. non-strategic nuclear weapons and 

delivery systems. These nuclear forces were removed as part of the 1991 

Presidential Nuclear Initiatives. The visible extension of the U.S. 

nuclear umbrella over the ROK is today provided by the “continuous 

presence” of U.S. bombers rotating through Guam, as well as SLBMs 

aboard nuclear submarines patrolling the Pacific. In 2011, the U.S. and 

the ROK established an Extended Deterrence Policy Committee as a 

formal mechanism for discussing alliance extended deterrence matters.

The ROK-US defense relationship is currently undergoing a 

period of transition, with Seoul preparing to develop long-range strike 

assets that may make it less dependent on U.S. forces and also assuming 

increasing responsibility for peninsular defense. The United States 

recently agreed to change “guidelines” between the two countries 

restricting the capabilities of ROK missiles and unmanned aerial 

vehicles. Seoul can now develop missiles with a range of up to 800 km, 

allowing it to rapidly strike targets across most of the DPRK, a capability 
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it believes will significantly strengthen its ability to directly deter 

Pyongyang.302 In addition, the United States and the ROK have 

developed a “Strategic Alliance 2015 Roadmap” whereby “wartime 

operational control” of Korean troops – currently a joint U.S.-ROK 

responsibility – will shift entirely to ROK military commanders in 

2015.303

Australia. The United States and Australia are longtime allies, 

the two countries signed a legally binding “Security Treaty between 

Australia, New Zealand and the United States of America” in 1951 (New 

Zealand is a defense partner of both states, but as discussed earlier is no 

longer an active member of the ANZUS Treaty). By Article IV of the 

treaty, both countries pledge “that an armed attack in the Pacific Area on 

any of the Parties would be dangerous to its own peace and safety and 

declares that it would act to meet the common danger.”304 In late 2011, 

the two countries agreed to amend the treaty to add the cyber domain as 

an additional area of common defense in the event of an attack on either 

party.305 Australia views its alliance with the United States – and the 

latter’s continued close engagement with the Asia-Pacific – as vital to 

both its national security and regional stability.306 It is also cautious, 

however, to balance this alliance with concerted diplomatic efforts to 

maintain good relations with China, which is critical to the Australian 

economy. 

The United States provides assurance to Australia through 

regular joint exercises – the annually held Talisman Saber exercise, for 

example, features over 20,000 U.S. and Australian troops – and rotations 

of military forces. The two countries recently concluded a major defense 

agreement placing a significant number of U.S. Marines on regular 

rotations in Northern Australia.307 The United States also assures 

Australia by including the country under its nuclear umbrella. The 

Australian government views U.S. extended nuclear deterrence as critical 

to its national security and a guarantee that has allowed the country to 

enjoy protection from nuclear attack without having to consider 

developing its own independent deterrent capability. As a recent 

Australian defense white paper explains:

Australian defence policy under successive governments 

has acknowledged the value to Australia of the 

protection afforded by extended nuclear deterrence 

under the US alliance. That protection provides a stable 

and reliable sense of assurance and has over the years 

removed the need for Australia to consider more 

significant and expensive defence options.308
129

Key Issues for Asian-Pacific Extended Deterrence and Assurance 

Strategies

The effectiveness and viability of U.S. extended deterrence and 

assurance strategies in the Asia-Pacific will face a number of near- and 

long-term tests within this dynamic and volatile region. 

The United States currently provides a visible nuclear extended 

deterrent capability in the form of B-52 and B-2 bombers rotating 

through Guam and patrolling the skies over the Western Pacific.309 This 

strategy of maintaining a “continuous presence” of visible U.S. aircraft in 

the Asia-Pacific ensures that potential adversaries are always aware the 

United States has nuclear-capable forces in theater. The strategy, 

however, faces challenges from both allies and adversaries. Some 

politicians and commentators in Japan and ROK, for example, have 

either argued for their own countries to develop an independent nuclear 

deterrent or called for the United States to permanently station nuclear 

forces on their territory. These calls represent an implicit challenge to 

the assurance value of the “continuous presence” strategy and its reliance 

on nuclear capable forces that are visible within the region, but 

geographically distant from the countries they are intended to protect. 

Second, if the nuclear and ballistic missile arsenals of potential 

adversaries within the region continue to grow, and if these actors 

continue to improve their A2/AD capabilities, allies and adversaries may 

begin to question the deterrent value of U.S. strategic bombers rotating 

through Guam, as these aircraft are limited in number and may be 

viewed as vulnerable on this central landing and transit point for their 

operations within the Asia-Pacific theater. 

In addition, the extended deterrence mechanisms established 

with Japan and the ROK have addressed both allies’ increasing interest 

in close engagement with the United States on nuclear deterrence issues. 

In the near-term, their establishment and early sessions have assured both 

parties of the U.S. commitment to maintaining a nuclear umbrella over 

their respective states. In the future, however, the United States will 

have to prepare for increasingly sophisticated questions from allies on 

nuclear strategies and plans, as well as increasingly detailed requests 

regarding what Tokyo and Seoul view as necessary for their defense. 

While these mechanisms are likely to increase the closeness of the 

defense relationship with both countries, the United States will also need 

to prepare for the likelihood that it may have to deny some of these 

requests. In short, an unquestioning acceptance of the U.S. nuclear 

extended deterrent – a long-standing status quo that suited the interests 

of Washington, Tokyo, and Seoul – no longer exists. This may not 

necessarily raise doubts within allied capitals about the nuclear umbrella, 
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but on this and other fronts, the United States and these allies are 

entering a new and untested phase of their defense relationship. 

More broadly, the credibility of U.S. extended deterrence and 

assurance strategies across the Asia-Pacific will hinge on two factors: 1) 

clear development and communication of the strategy and force structure 

implications of the “rebalance” to the region, and; 2) the U.S.-China 

relationship and the degree to which it is characterized by strategic 

stability. 

Both allies and adversaries remain uncertain of the full 

implications of the January 2012 “rebalance.” In general, Asian-Pacific 

capitals have viewed this development – and recent decisions to increase 

U.S. force rotations in Australia, Singapore, and elsewhere – through the 

lens of their existing relationship with the United States. Significantly, 

key allies such as Australia have quietly expressed support for these 

moves while simultaneously preaching caution in regard to their

potential impact on China. Allies and partners hope for a stable balance 

between the U.S. and China in the Asian-Pacific, but believe this will 

likely represent a delicate relationship for some time to come. 

For the United States, the challenge may ultimately prove to be 

one of available resources, even with an increased emphasis on the 

region. Regional adversaries are clearly attentive to, and concerned by, 

the U.S. conventional, nuclear, and missile defense presence in the AsiaPacific. The deterrent value of these forces, however, may diminish if 

they are dispersed across the region. At the same time, their assurance 

value will not be high if the United States cannot convince its numerous 

but scattered allies and partners that it has sufficient resources for their 

defense. For the foreseeable future, this will prove a continual challenge 

for U.S. military officials, defense planners, and diplomats responding to 

both security challenges and allied requests in this strategically vital 

region. 

Middle East

Extended Deterrence 

Within the Middle East, the United States extends deterrence 

against Iran and Syria. Due to Iran’s nuclear weapons program, recent 

U.S. policy statements and defense activities relevant to extended 

deterrence have focused on that country.

Iran. Iran views itself as a regional hegemon and is prepared to 

intimidate, coerce, or attack any Middle Eastern state that challenges its 

authority or aligns with a major power opposed to this vision. Since the 
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1979 Islamic Revolution which ousted a pro-U.S. government, Iran has 

represented an implacable adversary of the United States and of U.S. 

friends throughout the region, including Israel and Saudi Arabia. Its 

ongoing efforts to develop nuclear weapons, expand its ballistic missile 

arsenal, and provide critical financial and military backing to terrorist 

and insurgent groups pose direct threats to regional stability and U.S. 

security partners across the Middle East. 

Official statements and policy guidance from the Obama 

administration have repeatedly stressed the enduring importance of 

deterring Iran from attacking U.S. friends in the region, while also 

providing additional detail to past expressions of U.S. extended 

deterrence commitments across the Middle East. The 2012 DSG, for 

example, in addition to stressing the importance of preventing Iran from 

acquiring nuclear weapons, also called attention to Tehran’s “efforts to 

pursue asymmetric means to counter our power projection 

capabilities.”310

The United States extends deterrence against Iran by maintaining 

a significant military presence within the region. A number of Middle 

Eastern states in the region quietly (and unofficially) host either forwarddeployed forces or advance stores of U.S. military equipment on their 

territory.311 While the United States has no arrangements in the Middle 

East akin to the agreements with allies in Europe or East Asia permitting 

permanent U.S. bases on their territory, the U.S. Navy’s Fifth Fleet 

continually operates within the strategically vital Persian Gulf out of port 

facilities made available by Bahrain. The significant number of naval 

vessels, including aircraft carriers carrying fighter-bombers capable of 

striking a broad range of strategically important Iranian facilities, grants 

the United States the ability to extend deterrence against Iran without 

maintaining a significant regional footprint in terms of Army or Air 

Force offensive strike assets. 

The Obama administration has also sought to extend deterrence 

against Iran by bolstering U.S. regional missile defense capabilities, 

asserting that these systems play a critical assurance and extended 

deterrence role within the region. The 2010 BMDR states that Tehran’s 

propensity for taking risks cannot be completely offset through the threat 

of attacks by U.S. offensive forces. It argues that pairing these forces 

with defensive systems capable of negating Iran’s weapon of choice will 

significantly improve the ability of the United States to deter Tehran 

from threatening or attacking U.S. regional security partners.312

In addition to extending deterrence against Iranian efforts to 

harm U.S. friends in the Middle East, the United States also extends 

deterrence against Iran’s repeated threats to constrain and deny access to 
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the Persian Gulf by U.S. naval forces and international shipping. The 

United States is determined to deter Iran and any other state that attempts 

to restrict freedom of navigation in international waters. The robust U.S. 

naval presence in the Middle East – supplemented by exercises and 

operations reacting to Iranian threats to close the Straits of Hormuz or 

attack vessels in the Persian Gulf – are intended to send clear signals to 

Tehran that it will pay a price for attacking U.S. naval forces, 

commercial shipping, or any other vessels using this strategically vital 

waterway.

Syria. The United States also extends deterrence against Syria, in 

part because Tehran and Damascus partner together to form an anti-U.S., 

anti-Israel, pro-Hezbollah coalition. Even prior to the Syrian civil war, 

Obama administration statements generally underlined longstanding U.S. 

efforts to deter Syria from interfering in internal affairs in Lebanon and 

attacking Israel.313 The 2010 BMDR also noted the regional threat posed 

by Syria’s ballistic missile arsenals (it did not, however, give Damascus 

the same “risk taking” label it attached to Tehran).

314

 The situation 

within Syria remains fluid at the time of this writing. The United States 

has recently bolstered its military support to both Turkey and Jordan as 

they attempt to assist Syrian refugees and address the broader regional 

security implications of the ongoing civil war.315

No Regional Nuclear Umbrella. The United States does not 

officially extend a “nuclear umbrella” to assure any of its friends in the 

Middle East and does not publicly employ any nuclear strategies for the 

purposes of regional extended deterrence. It does not station nuclear 

forces in the region (as it does in Europe) nor does it maintain a 

continuous presence of nuclear forces in the Middle East (as it does in 

the Pacific). However, as Secretary of State Hillary Clinton stated in 

2009,

We want Iran to calculate what I think is a fair 

assessment, that if the U.S. extends a defense umbrella 

over the region, if we do even more to support the 

military capacity of those in the Gulf, it’s unlikely that 

Iran will be any stronger or safer, because they won’t be 

able to intimidate and dominate, as they apparently 

believe they can, once they have a nuclear weapon.316

This has led to speculation the United States – in addition to 

putting all options on the table for halting Iran’s nuclear program – may 

be developing, and considering the implications of openly stating, 

extended nuclear deterrence plans expressly tailored for the Middle 
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East.317 While experts have noted significant obstacles to implementing 

either the NATO or Asia-Pacific models of extended deterrence to the 

Middle East, one approach suggested for the region is the future 

designation of an ICBM squadron or some number of SLBMs for 

addressing a potential nuclear threat from Iran.318

Assurance 

The 2012 DSG, while stating that the United States will 

“rebalance” to the Asia-Pacific, also stressed that Washington will not 

neglect its defense commitments to the Middle East, asserting “[the] 

United States will continue to place a premium on U.S. and allied 

military presence in – and support of –– partner nations in and around 

this region.”319 The Obama administration has stated that the United 

States will “renew focus on a strategic architecture” in the Middle East to 

extend deterrence and provide assurance “while [also] balancing that 

requirement against the regional sensitivity to a large, long-term U.S. 

force presence.”320

The United States does not have a formal alliance with any state 

or coalition in the Middle East, with the exception of Turkey (a member 

of NATO since 1952). Its provision of assurance to states within the 

region is primarily realized through longstanding, often informal, defense 

arrangements that are sometimes based on personal diplomacy with 

national leaders. Military sales, joint exercises, and other forms of 

defense cooperation are also critical to many of these relationships. This 

reflects the myriad number of national rivalries that preclude close 

cooperation between many Middle Eastern governments, even in the face 

of the common threat posed by Iran. The necessarily patchwork nature 

of U.S. assurance policies and strategies in the Middle East reflects the 

geopolitical reality of a starkly divided region where the U.S. military 

represents the primary provider of security to many states, but the 

formation of a regional treaty-based alliance is politically and 

diplomatically unlikely. 

Israel. Israel faces a broad range of regional security threats, to 

include Iran’s nuclear weapons program and ballistic missile arsenal, 

rocket attacks launched by Hezbollah from its bases within Lebanon, and 

rocket and terrorist attacks from Palestinian organizations such as 

Hamas. In addition, the Israeli-Palestinian peace process has made no 

recent progress, with the Israeli government and Palestinian Authority 

remaining at an impasse over territorial boundaries and other issues. The 

country is also the target of bellicose rhetoric from Iran, Syria, and other 
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Middle Eastern states, and its relations with Turkey have recently soured; 

at present, it only has peace treaties with Egypt and Jordan. 

The United States has sought to assure Israel through a variety of 

means. President Obama has repeatedly stated that “Israel’s security is 

sacrosanct [and] non-negotiable” and the 2012 DSG asserts the United 

States is firmly committed to “standing up for Israel’s security.”321 The 

Obama administration has maintained, and sought to enhance, a close 

relationship between the two countries’ militaries, with the two countries 

carrying out their largest-ever joint military exercise in October 2012.322

In addition, the United States has long represented the lead provider of 

military aid and assistance to Israel and the two countries closely 

cooperate on intelligence matters. In order to better address the specific 

threat posed to Israel by ballistic missiles and rockets, Tel Aviv and 

Washington agreed to co-produce the Arrow missile defense system, and 

the Obama administration has also provided significant financial support 

for Israel’s Iron Dome defense system against rocket attacks.323

Gulf Cooperation Council. The United States has a variety of 

security partnership arrangements with the six members of the Gulf 

Cooperation Council (GCC): Saudi Arabia, Oman, Qatar, United Arab 

Emirates (UAE), Bahrain, and Kuwait. Bahrain also hosts the U.S. 

Navy’s Fifth Fleet. The United States is committed to partnering with 

the GCC to counter Iran (with a specific emphasis on Tehran’s nuclear 

program), combat extremist organizations such as al Qaeda, and address 

the threat posed by regional missile proliferation.324 The United States 

also provides assurance to the GCC through sales of military hardware. 

U.S. military sales of advanced systems such as F-15 fighter aircraft to 

GCC members are expressly intended to help equip these U.S. friends to 

better address potential regional security threats.325

With GCC states increasingly concerned about Iran’s growing 

ballistic missile arsenal, the United States maintains a “continuous 

missile defense presence” in the region.326 It is also working with GCC 

members to explore expanding current air defense cooperation between 

the U.S. and individual members into a council-wide, networked 

approach to missile defenses.327

Egypt, Lebanon, and Jordan. The United States is also a security 

partner of Egypt, Lebanon, and Jordan “to counter extremism and other 

regional threats,” although its defense relationship with Cairo is in a state 

of flux as a result of the Arab Spring and ongoing uncertainty about 

Egypt’s future.

328 The United States is the lead provider of military aid 

to Egypt and, in recent years, has provided critical funding to assist the 
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development of Lebanon’s armed forces and improve the ability of the 

Lebanese government to police its own borders.329 As noted above, the 

United States has recently taken steps to assure Jordan in light of the 

dangerous and unstable situation within Syria. 

Key Issues for Middle East Extended Deterrence and Assurance 

Strategies

Four successive U.S. presidents have declared that Iran will not 

be allowed to develop a nuclear weapons capability. An Iranian nuclear 

capability would pose a clear and direct threat to U.S. allies and partners 

in the Middle East, Near East, and Europe. The United States has also 

cited the Iranian regime as a state sponsor of terrorism and a state likely 

to take risks in the future, particularly given its growing ability to 

threaten regional states with ballistic missiles. Iran has also become 

deeply involved in the ongoing Syrian civil war, providing substantial 

assistance to the Assad regime. 

Should Iran develop a nuclear arsenal, the United States will 

need to develop a robust extended deterrence strategy for the Middle 

East that takes into account uncertainty regarding the nuclear deterrence 

calculations of Iran’s leadership and Tehran’s dedicated efforts to harden 

many key nuclear production and military facilities. It is unclear what 

concept the United States might employ for extending deterrence in the 

region, the Middle East’s deep divisions rule out the formation of a 

formal alliance encompassing the United States’ regional security 

partners. The United States lacks the relevant agreements, facilities, and 

close defense cooperation with allies required for a region-wide model 

similar to NATO’s nuclear sharing arrangements. In addition, the 

“continuous presence” model employed in the Asia Pacific cannot be 

readily applied due to the lack of a location analogous to Guam (in terms 

of its strategic location, its political relationship to the United States, and 

as a host of extensive permanent U.S. military facilities). Moreover, the 

United States encounters significant diplomatic and security challenges 

in even deploying conventional forces in theater. It is difficult to 

imagine a situation where a Middle Eastern state – outside of NATO 

member Turkey – might request or allow the U.S. military to base 

nuclear-capable forces on its territory (and where the United State would 

feel comfortable doing so). In addition, for as long as Iran remains on 

the brink of a nuclear capability, the continuing question of what 

threshold of Tehran’s progress towards a weapon triggers a U.S. or 

Israeli military response will remain open and the subject of intense 

debate in capitals across the region.
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Tehran’s ballistic missile arsenal also poses a challenge to U.S. 

deterrence-by-denial strategies. The United States and its regional 

partners are unlikely in the near future to field sufficient interceptors to 

address the number of missiles deployed by Iran.330 The United States 

will need to consider how to develop allied and regional deterrence 

strategies that include but do not rely on missile defenses. 

The U.S. drawdowns from Iraq and Afghanistan, and the 

“rebalance” toward the Asia-Pacific, are raising a number of assurance 

questions from U.S. partners across the Middle East.331 With the United 

States’ security relationships in the region largely dependent on informal 

arrangements, Washington will likely need to consider what political and 

military signals, actions, and capabilities can assuage concerns that the 

United States is turning its attention elsewhere. This is a particularly 

important consideration at a time when Iran is close to a nuclear weapon, 

Syria is engaged in a bloody civil war, the Israeli-Palestinian peace 

process remains stalled, Turkey’s strength and regional influence is on 

the rise, and the repercussions of the Arab Spring are still reverberating 

across the region. Addressing the anxieties of regional partners, while 

also deterring a belligerent Iran and a wounded-but-dangerous Syria, will 

require carefully tailored strategies leveraging a broad range of U.S. 

diplomatic and military capabilities. 

NATO/Europe

NATO remains critical to U.S. security. U.S. guidance 

documents highlight this continuing reality, despite recent emphasis on 

the security challenges of the Middle East and the so-called pivot toward 

the Asia-Pacific. U.S. extended deterrence and assurance arrangements 

for NATO are well-established but, as discussed earlier, have evolved 

over from the Cold War to the present day, and a brief overview is 

provided here before addressing current issues. 

Extended Deterrence

NATO Extended Deterrence Strategies and Forces During the 

Cold War. The first formalized extended deterrence arrangement of the 

modern era was created by the 1949 Washington Treaty. This established 

the North Atlantic Treaty Organization, a collective defense entity that 

included the United States, Canada, and multiple European states. The 

United States was the only nuclear member at the time NATO was 

created; today, the United Kingdom and France are also nuclear weapons 

states. 

The grand bargain between NATO’s member states was that the 

United States would guarantee the security of the other members as long 
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as all contributed to the general defense – a process called risk- and 

burden-sharing. This guarantee included the full weight of America’s 

military forces, up to and including nuclear weapons. In addition, by the 

mid-1960s the alliance had created a process for nuclear sharing between 

all member states, including the Nuclear Planning Group (NPG) which 

meets regularly in Brussels to discuss nuclear weapons and strategy in a 

collaborative environment (France is not a participant in the NPG). 

The military forces of the United States a forward deployed in 

Europe. This provided a trip wire warning of any Soviet advances into 

NATO territory. Military forces, plus their families and dependents, 

meant that there were several million U.S. personnel stationed in Europe 

at the height of the Cold War, a situation that assured the allies the 

security of the United States was “coupled” to that of Europe. 

The military forces of NATO were designed to create a seamless 

web of deterrence, and plans were in place to respond to a provocation at 

any point on the so-called ladder of escalation, from the lowest level of 

conventional conflict through large-scale conventional war, to battlefield 

use of nuclear weapons, to theater use, and up to a strategic nuclear 

exchange, if necessary. In order to meet the overwhelming advantage of 

the Warsaw Pact in terms of conventional force numbers, the alliance 

had a policy of deliberate escalation of a conflict. The theory was that by 

threatening to make the war more costly, it would deter the adversary 

from taking the first step. Of course, this also meant that the alliance 

required the capabilities necessary to ensure escalation dominance at the

next higher level of violence; otherwise the theory would not work. 

In addition to the 300,000 American troops in Europe in the 

1960s and 1970s, with their associated hardware, including thousands of 

tanks, fighter aircraft, field artillery, anti-aircraft missile batteries, 

helicopters, armored personnel carriers, and other military equipment, 

the United States also deployed tactical nuclear weapons in the theater. 

Building from initial nuclear deployments to Europe in 1953, the U.S. 

military eventually had some 7,300 nuclear warheads in hundreds of 

storage locations across Central Europe and the Mediterranean available 

for use by 11 separate delivery systems, from 155mm howitzer shells to 

gravity bombs for aircraft to atomic demolition munitions to warheads on 

Jupiter IRBMs. Through an arrangement called the dual-key approach, 

host nations not only allowed weapons to be stored on their territory, but 

also shared responsibility for weapons delivery. A national delivery 

system (typically an aircraft or artillery unit) would be mated with a U.S. 

warhead in wartime. In addition, a certain number of sea-based nuclear 

weapons of the United States and United Kingdom were dedicated to the 

alliance, and the UK’s entire triad was also committed to NATO plans. 
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At one time or another, ten NATO members have had a nuclear delivery 

mission, underscoring the scope of the military threat to the alliance 

posed by the Soviet bloc and the vital role nuclear weapons played for 

decades within NATO’s deterrence and defense strategies. The arsenal 

size fell precipitously after the end of the Cold War, leaving a relatively 

limited number of non-strategic nuclear forces in Europe backed by U.S. 

and UK strategic forces. 

NATO Extended Deterrence Strategies and Forces Today. 

NATO is now an alliance of 28 members, to include several states that 

were formerly members of the Warsaw Pact. The United States remains 

the alliance’s strongest member and is heavily involved in every level of 

alliance policymaking and strategizing. The 2010 QDR noted that 

European security has remained central to American national interests 

for much of the past century, and pledged to “work to ensure a strong 

NATO that provides a credible Article 5 security commitment [and] 

deters threats to Alliance security,” to include threats such as ballistic 

missile proliferation and cyber-attacks.332 In addition, the 2012 DSG 

asserts that Europe remains important to U.S. national security, stating 

“Europe is our principal partner in seeking global and economic security, 

and will remain so for the foreseeable future.”333 While acknowledging 

that the U.S. defense posture in Europe has changed significantly from 

the end of the Cold War, the 2010 QDR noted the regional and global 

importance of keeping significant U.S. military forces in theater:

Maintaining a robust U.S. military presence in Europe 

serves to deter the political intimidation of allies and 

partners; promote stability in the Aegean, Balkans, 

Caucasus, and Black Sea regions; demonstrate U.S. 

commitment to NATO allies; builds trust and goodwill 

among host nations; and facilitates multilateral 

operations in support of mutual security interests both 

inside and outside the continent.334

Furthermore, out of theater, troops from a number of NATO 

states continue to serve and fight side-by-side with U.S. forces in 

Afghanistan. The International Security Assistance Force in Afghanistan 

is, in fact, a NATO operation.

However, although the transatlantic link provided by NATO 

between the United States and the alliance’s European members remains 

in place, a number of American and European analysts question whether 

the concept of coupling remains strong in the post-Cold War period. The 

U.S. military footprint in Europe has been reduced dramatically to reflect 

the changed international security environment since the end of the Cold 
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War.335 In addition, the recent declaration by the Obama administration 

that the United States would rebalance its national security strategy, 

placing more emphasis on the Asia-Pacific region, has led to the open 

question – voiced by strategic communities on both sides of the Atlantic 

– whether this shift will necessarily require the United States to pivot 

away from Europe.

In addition to questions about the future U.S. role within Europe, 

the alliance also continues to face the broader question of how to adapt to 

a geopolitical environment where its members no longer face the direct 

threat of a potential land invasion by massed conventional forces, but 

must adapt to counter a variety of indirect threats and future challenges, 

to include the proliferation of WMD and cyber warfare. The alliance has 

officially agreed to field conventional, nuclear, and missile defense 

forces (to include a future system capable of defending the whole 

alliance),336 and develop cyber capabilities, in order to address a broad 

range of threats and contingencies.337 Neither the United States nor the 

alliance, however, currently extend deterrence against any specific state 

actor in order to deter them from attacking members of NATO. The 

alliance, for example, officially seeks peaceful engagement with 

Moscow, with guidance documents such as NATO’s 2010 Strategic 

Concept stating “NATO-Russia cooperation is of strategic importance as 

it contributes to creating a common space of peace, stability and security. 

NATO poses no threat to Russia.”338 

Assurance

Although NATO does not at present face a direct military threat,

the alliance believes the current “security environment ... contains a 

broad and evolving set of opportunities and challenges” for its members, 

to include potential threats posed by WMD and ballistic missile 

proliferation, non-state actors, and failed states.339 While U.S. forces 

stationed in Europe continue to decline in terms of overall numbers, the 

United States is firmly committed to providing assurance to its NATO 

allies by retaining nuclear and conventional forces in theater. Moreover, 

the United States and NATO are developing concepts and forces to 

provide the alliance with a future missile defense shield capable of 

protecting Europe against the ballistic missile arsenals of states such as 

Iran.

The risk of nuclear attack against NATO members is at an 

historic low. Yet nuclear weapons still serve a political purpose that 

assures U.S. allies and can provide a deterrent against unspecified future 

existential threats. As the 2010 NPR put it,
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the presence of U.S. nuclear weapons – combined with 

NATO’s unique nuclear sharing arrangements under 

which non-nuclear members participate in nuclear 

planning and possess specially configured aircraft 

capable of delivering nuclear weapons – contribute to 

Alliance cohesion and provide reassurance to allies and 

partners who feel exposed to regional threats.340

Furthermore, the United States affirmed that it would not make 

unilateral decisions as to the future of those weapons or their basing in 

Europe. “Any changes in NATO’s nuclear posture should only be taken 

after a thorough review within and decision by – the Alliance.”341 The 

United States stated that it would work with its NATO allies to continue 

to reduce the role of nuclear weapons in international relations, but it 

also pointedly stated that as long as those weapons exist anywhere in the 

world, NATO would remain a nuclear alliance. In the near term, the 

United States agreed that it would retain the necessary weapons and 

delivery systems to continue to provide a dual-key nuclear sharing 

arrangement with its allies in Europe. At present, the U.S. force 

contribution to these sharing-arrangements are U.S. dual-capable aircraft 

stationed in Europe and B-61 gravity bombs.342 With strong U.S. 

support, NATO recently reconfirmed its intent to “remain a nuclear 

alliance for as long as nuclear weapons exist.”343 

In addition, missile defenses have played an increasingly

important role in U.S. assurance to NATO. The 2010 BMDR 

highlighted the United States’ close cooperation with NATO allies on the 

development of a European Phased Adaptive Approach (EPAA) to 

establish a future missile defense capability to protect against the ballistic 

missile arsenals of states of concern outside of Europe. According to the 

guidance document, “The United States is committed to making the PAA 

its national contribution to a NATO missile defense effort.”

344

 The 2010 

BMDR also pointed out that, in addition to these NATO-wide 

consultations, the alliance members Czech Republic and Poland had 

concluded bilateral agreements with the United States to host key missile 

defense components.345 Romania and Turkey have also agreed to host 

PAA components. 

Key Issues for NATO Extended Deterrence and Assurance 

Strategies

A key question for the United States in the context of extended 

deterrence in Europe is quite simple: Who is being deterred? The 

alliance has expressly stated that Russia is not an enemy; in fact, it is a 

strategic partner of NATO. Still, the real threats facing NATO today are 
141

the possibility of a resurgent Russia, the rise of a nuclear-armed Iran, and 

the general uncertainty as to what surprises the international environment 

might bring in the future. 

There are quite differing views within NATO on nuclear 

deterrence and on the military utility of non-strategic nuclear weapons 

for the alliance. The debate over the future of these weapons in Europe 

has spilled out into public forums over recent years, with Germany and 

the Low Countries in favor of changes to current nuclear-sharing 

arrangements and France, Britain, and the East European member states 

in favor of keeping DCA and U.S. warheads on the continent. Much of 

this debate was papered over by the DDPR’s May 2012 announcement 

that, by consensus agreement, the alliance had determined that the status 

quo of current nuclear, risk- and burden-sharing arrangements are 

sufficient and necessary conditions for NATO deterrence. Those who 

favor the existing arrangements and are generally pro-nuclear have called 

this a major victory for the alliance – the first time in many years that 

members were able to reach a consensus in support of maintaining 

current NATO nuclear policy. Other NATO states are less sanguine, 

seeing this as but a pause on the general path toward the end of U.S. 

nuclear weapons stationed in Europe – although not necessarily the end 

of nuclear policy within the alliance. 

NATO has three nuclear weapons states among its members. 

The United Kingdom has reduced its nuclear arsenal to 180 warheads 

dedicated to its small fleet of Trident submarines. France retains some 

300 nuclear warheads for national use, but it remains apart from alliance 

military planning.346 That status is unlikely to change even if all 

remaining U.S. weapons were someday to be withdrawn from European 

territory. NATO’s future nuclear sharing arrangements, however, may 

be at risk. At present, nuclear forces remain an important part of alliance 

defense strategies. Today, according to open sources, there are still five 

European member states that have dual-key arrangements with the 

United States or store U.S. nuclear warheads on their territory (in 

addition to the alliance’s three nuclear member states).347 There are 

officially “several hundred” U.S. warheads stored in Europe. How many 

U.S. nuclear weapons will need to remain stationed in Europe to 

maintain assurance of NATO allies into the future, however, is uncertain. 

It may require the “several hundred” still forward deployed, or it may 

only take one or two weapons to ensure the continued coupling of U.S. 

and European security. Or perhaps the answer is none – the United 

States could make the same political commitment to Europe that it has 

made for the past two decades to its East Asian allies, with no 

requirement for nuclear weapons permanently stationed in theater. If 
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U.S. weapons remain, the United States and members of the alliance 

must also address the status and role of their respective delivery systems. 

As discussed above, current U.S. and allied nuclear-capable aircraft are 

aging, and their intended replacement, the F-35, has encountered a 

number of problems in its development phase. 

Another potential issue is whether America’s European allies –

especially Eastern European members of NATO – will remain assured as 

the United States continues to draw down its conventional forces in 

Europe. In particular, how do the alliance and the United States, 

bilaterally, assure Turkey, given that country’s apparent shift from a 

European to a Middle Eastern perspective? A number of studies find that 

Turkey no longer feels as much a part of Europe – or NATO – as it once 

did. In part, this is due to pessimism over whether its European partners 

in NATO would come to its defense, given memories of alliance 

reticence to do so in 1991 and 2003, and the varying responses of the 

United States and European capitals toward the Syrian civil conflict. It 

also reflects growing Turkish confidence in its ability to act as an 

independent regional power that can play an important role in both 

European and Near Eastern affairs, and develop unique policies and 

strategies for addressing actors such as Iran. In addition, the Turkish 

public appears open to a future debate on independently developing a 

nuclear weapons program if Iran becomes a nuclear state. Ankara is 

unlikely to embark on this path in the near- or medium-term, but the poll 

numbers are significant in reflecting a general lack of faith in NATO 

nuclear-sharing arrangements and the U.S. nuclear umbrella.348

With regard to nuclear delivery systems, a major future 

stumbling block to retaining nuclear sharing arrangements will arise as 

allied DCA in some countries reach their retirement age and require 

replacement in the 2020s. The replacement programs, if there are to be 

any, have yet to be budgeted, and there is no guarantee that the nuclear 

sharing arrangements will still be in place in NATO ten years hence. 

Furthermore, the EPAA faces two significant challenges. First, 

program delays and funding issues led the Obama administration to 

decide in early 2013 not to develop the SM-3 IIB interceptor critical to 

plans for the system’s Phase IV.

349

 Phase III will have capabilities to 

defend against short, medium, and intermediate-range missiles. Phase IV 

was initially intended to provide a system with boosted capabilities for 

addressing intermediate-range delivery systems.350 The decision to drop 

a significant phase of system development underlines the long-term 

budgetary, technical, and program management challenges faced by the 

EPAA. Second, Russia has repeatedly stated that it is deeply concerned 

the EPAA will threaten strategic stability with Washington and with 
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NATO more generally, raising objections to the location of system 

components in Eastern Europe and to the system’s future capabilities. 

These objections have remained in place despite the U.S. announcement 

it was dropping Phase IV, which was the focus of earlier Russian 

arguments about the completed EPAA undermining its strategic nuclear 

deterrent. 

These challenges raise a number of questions for NATO. Is 

EPAA worth the expense it will take to develop, particularly given the 

ongoing defense cuts across the alliance? In addition, if NATO missile 

defenses appear to threaten strategic stability with Russia before a clear 

missile threat to Europe arises (such as that from Iran), does missile 

defense continue to have value for extended deterrence and assurance 

strategies – or does it undermine one or both? For the moment, the 

alliance has decided the EPAA is worth pursuing, and they are going 

through with plans to deploy a robust, layered, missile defense 

architecture in Europe within the coming decades. If Russia were to 

attempt to ratchet up the pressure on NATO, however, such as through 

the selective embargo of oil to certain states or the alliance as a whole, it 

is difficult to assess how different European governments would react 

and whether these actions would stiffen or weaken their commitment to 

missile defenses.

Questions about missile defense funding are related to perhaps 

the biggest long-term issue for alliance deterrence strategies: will NATO 

allies maintain the capabilities necessary to meet deterrence challenges, 

particularly if the United States continues to press these states, and other 

allies, to take on a greater share of defense and deterrence 

responsibilities? NATO members face a dual challenge in addressing 

future threats; first, many members and their respective public’s view 

NATO as a “relic of the Cold War” and, second, despite Secretary of 

Defense Robert Gates’ blunt challenge to the allies to improve their 

military capabilities, it still “lacks a sustainable burden-sharing model 

which could reduce the risk of a further disintegration of the alliance.”351

These will represent considerable obstacles to U.S. efforts to develop 

deterrence and assurance and strategies for NATO that can align U.S. 

policy imperatives, mesh with allied defense capabilities, and address 

threats that, while serious, are far more amorphous and difficult to 

directly confront than a direct military adversary of the alliance. 
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PART 7: CONCLUSION

This paper differentiated the concepts of deterrence, extended 

deterrence, and assurance (Part 2); provided an historical overview of 

U.S. deterrence, extended deterrence, and assurance strategies (Part 3);

and assessed continuity and change with regard to these strategies over 

time (Part 4); discussed current U.S. extended deterrence and assurance 

strategies (Part 5); and presented an overview of issues regarding 

extended deterrence and assurance in three regions of key importance to 

the United States: the Asia-Pacific, the Middle East, and Europe (Part 6). 

Across these sections, it has sought to communicate the enduring 

importance of U.S. allied assurance and extended deterrence strategies to 

allied security, regional stability, and, in turn, to U.S. peace and 

prosperity. Despite significant geopolitical changes from the Cold War 

to the present day, these strategies remain critical to U.S. allies across the 

globe. Many of those allies face potential adversaries fielding superior 

conventional capabilities, WMD, or both. Global in scope, extended 

deterrence and allied assurance strategies require the United States to 

remain vigilant in protecting allies from a range of threats and flexible in 

fielding a variety of forces capable of conducting numerous (and often 

simultaneous) deterrence operations against a multiple potential 

adversaries.

This paper finds that U.S. extended deterrence and allied 

assurance strategies face a number of significant near- and medium-term 

challenges that, if unaddressed, may result in foreign actors – both allied 

and adversary – raising serious questions about the credibility of U.S. 

security guarantees. Some of these challenges represent oft-repeated 

questions from allies and adversaries. Many of those questions represent 

variations on issues fundamental to the phenomena of extended 

deterrence and assurance: why would a state risk blood and treasure on 

behalf of a third party, and how much risk on their behalf is it willing to 

accept? Other questions address more recent issues brought about by 

geopolitical change, the actions of potential adversaries, and/or U.S. 

policy and strategy decisions. 

This paper concludes by highlighting three challenges for U.S. 

extended deterrence and allied assurance strategies that serve as 

exemplars of the broader problem set that U.S. policymakers, strategists, 

and planners must address in the present complex geopolitical 

environment. 

One enduring challenge, first discussed in Part 4 as the “Healy 

theorem,” is the differing requirements of extended deterrence and allied 

assurance. The Healy theorem initially referred to U.S. debates with 

NATO allies who pressed for assurance strategies backed by greater 
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capabilities than the United States felt necessary to deter the Soviet 

Union. It broadly applies, however, to a perpetual challenge for U.S. 

policymakers and strategists: U.S. strategies and plans that assure ally X 

may differ from what is necessary to deter potential adversary Y. Given 

the large number of globally-dispersed allies the United States must 

assure – and in turn, their potential adversaries the United States must 

deter – the Healey theorem underlines the significant scope of the 

challenge facing the United States in developing extended deterrence and 

allied assurance plans and strategies. With both strategic concepts 

existing in the eye of the beholder, the United States must simultaneously 

tailor differing strategies addressing the assurance needs of each ally 

while also communicating and demonstrating the ability to impose 

unacceptable costs on each of their potential adversaries. The Healy 

theorem accurately describes the challenge of developing and managing 

regional assurance and extended deterrence strategies as a complex 

multivariable equation. It also helps delineate allied assurance and 

extended deterrence as related, but separate, strategic concepts, an 

important distinction sometimes absent from analyses of deterrence 

strategies and policies focused on foreign parties. Moreover, as 

impressed upon the authors by subject matter experts during interviews 

conducted for this paper, in a number of key cases the contemporary 

requirements of allied assurance remain more demanding than those of 

extended deterrence.

A second enduring challenge faced by the United States is 

convincing its numerous allies that it maintains more than enough

military forces to protect them from their prospective enemies, to include 

in circumstances where the United States is forced to simultaneously 

address more than one crisis or conflict (the “leaky umbrella” problem). 

The global responsibilities of the United States have always presented 

U.S. policymakers and strategists with difficult questions regarding 

when, where, and how to deploy finite defense resources. During the 

Cold War, for example, the massive destructive power of nuclear forces 

was frequently used by the United States to address significant gaps in 

conventional capability vis-à-vis the forces of the Soviet bloc. This 

challenge continues today. As the 2010 BMDR notes, for example, the 

United States and its allies fall far short of fielding sufficient missile

defense interceptors to meet the number of ballistic missiles fielded by 

potential adversaries. 

This ongoing challenge may assume a higher-profile in the nearterm, due to the U.S. commitment to defend the U.S. homeland, its 

friends abroad, and the “global commons” from a range of adversary 

threats, to include threats across air, land, sea, space, and cyber domains. 
147

While correctly acknowledging the broad scope of U.S. and allied critical 

assets and vital interests in the 21st century, this view of deterrence –

particularly as it becomes codified in agreements with allies, such as the 

decision to add cyber-attacks to the ANZUS common defense pact with 

Australia – may raise questions regarding whether the United States 

possesses enough military capabilities to meet all of these commitments. 

It may appear to foreign actors – both allied and adversary – that the 

United States has expanded the scope of requirements for deterrence, 

extended deterrence, and allied assurance while also reducing resources 

it has available for implementing these strategies. 

A third enduring challenge is calibrating the right role for 

nuclear forces in extended deterrence and assurance strategies. Over 

time, U.S. deterrence concepts have gradually shifted from an emphasis 

on deterrence by punishment strategies reliant upon nuclear weapons to 

strategies that include deterrence by punishment and deterrence by denial 

options using a mix of forces. At present, U.S. deterrence strategies 

continue to feature nuclear weapons but place increasing emphasis on the 

deterrence capabilities of missile defenses and advanced conventional 

weapons, with the former viewed as ceding some of its previous roles 

and responsibilities to the latter two types of forces. This raises two 

critical challenges for U.S. strategists in regard to extended deterrence 

and assurance. The first is that, for those U.S. non-nuclear allies facing 

nuclear-armed adversaries, U.S. nuclear forces remain vital to their 

defense against an existential threat. Plans or policies implementing a 

reduced role for nuclear forces in U.S. deterrence strategies must 

carefully clarify how non-nuclear forces can replace some of the strategic 

effects of the latter, while also reassuring allies that the U.S. nuclear 

umbrella continues to provide an effective deterrent against nuclear 

threats, coercion, or attacks. The second is to develop strategic concepts 

for explaining and implementing how mixed forces integrating the 

unique capabilities of conventional, nuclear, and missile defense 

components can effectively extend deterrence against a range of potential 

adversaries. Allies are likely to ask whether missile defenses, for 

example, can fulfill some or all of the responsibilities assigned in the past 

to nuclear forces, and to ask how the two can operate together to improve 

the ability of the United States to deter contemporary adversaries. 

The above challenges represent a few of the issues the United 

States will need to address as it reduces its post-9/11 military force, shifts 

its strategic attention to the Asia-Pacific, and seeks to reduce the role and 

numbers of its nuclear forces within its future defense strategies. These 

challenges stem directly from the ongoing U.S. role as primary security 

guarantor for allied states around the globe, who not only rely on the 
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United States but often shape their national security policies and military 

strategies in response to the decisions of their superpower ally. As a 

result, the credibility of U.S. extended deterrence and assurance 

strategies is a central feature of regional stability and also plays a key 

role in contemporary geopolitics. This paper finds that this places 

considerable responsibility upon U.S. policymakers, strategists, and 

planners tasked with developing and implementing these strategies to 

respond to multiple threats to the United States and its allies – and that 

this problem set has evolved, but become no less complex, over time. 
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APPENDIX: EXTENDED DETERRENCE LITERATURE REVIEW

Polly M. Holdorf

The following is a brief review of extended deterrence- and 

assurance- related literature from the past several years. Some of 

the main themes which occur throughout these articles include the 

continuing importance of extended nuclear deterrence, the 

challenges of extended deterrence and assurance in regional 

contexts, the dynamics of the current threat environment, and 

challenges facing policy makers.

Acton, James, “Extended Deterrence and Communicating Resolve,” 

Strategic Insights, Volume VIII, Issue 5, December 2009.

In this paper James Acton explores the question of how the 

United States can convince allies of its resolve to uphold its extended 

deterrence commitments. He states that the United States has 

“deliberately tried to conflate resolve and capabilities in allies’ minds in 

an attempt to demonstrate U.S. resolve through the provision of 

particular capabilities.”352 Acton asserts that the designation of specific 

nuclear capabilities will only assure allies effectively if those capabilities 

actually enhance deterrence. In the case of Japan, he argues that 

TLAM/N does not enhance deterrence because the capability itself does 

nothing to address Japan’s concern regarding the United States’ resolve 

to use nuclear forces in Japan’s defense. Further, Acton states that 

because the concepts of resolve and capabilities have come to be viewed 

by allies as interconnected, current U.S. nuclear doctrine calls for 

retaining more nuclear weapons than are required for deterrence. 

Acton claims that the key to extended nuclear deterrence is the 

effective communication of U.S. resolve. He calls for the development 

of a new communication strategy that does not rely on the provision of 

specific capabilities. Since the United States has a diverse range of 

allies, varying approaches will likely be required to convince different 

allies of the solidity of U.S. resolve. Acton highlights five points that 

should be considered while this new strategy is being developed. 1) 

Effective deterrence relies as much on culture as capabilities. 2) Allies 

should be consulted before decisions affecting them are taken. 3) Allies 

should be educated in nuclear strategy in order to disentangle the 

concepts of capabilities and resolve. 4) U.S. domestic dialogue can 

undermine allies’ perceptions of U.S. resolve. 5) It is important to be 
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realistic about the highly limited set of circumstances in which nuclear 

weapons are useful.

Bunn, Elaine, “The Future of US Extended Deterrence,” in Bruno 

Tertrais, ed, Perspectives on Extended Deterrence, (Paris: Fondation 

pour la Recherché Strategique, Recherches et documents no.3), March 

2010.

In the third chapter of Perspectives on Extended Deterrence

Elaine Bunn discusses the state of extended deterrence today, the 

prospects for extended deterrence in space and cyber space, the 

possibility of extending U.S. deterrence to the Middle East, and potential 

challenges to extended deterrence along the path to nuclear zero. Bunn 

counsels that threats from proliferating states and non-state actors could 

become even more serious in the future and asserts that the successful

maintenance of extended deterrence will require a strategic force 

structure that will both deter and assure across a wide range of actors, 

contingencies, and domains. 

While it is not yet clear how vulnerabilities in space and cyber 

space will affect the way deterrence is exercised, Bunn suggests that the 

United States and its allies will need to develop a better understanding of 

the unique characteristics of space and cyber space in order to deter 

potential adversaries from targeting those domains. Further, she offers 

that space capabilities developed in coalition with other states could 

enhance resilience, redundancy and operational continuity during 

military contingencies involving counter-space attacks. 

Extended deterrence to friends and allies in the Middle East 

could prove difficult, particularly due to the possibility that widespread 

public disapproval of U.S. forces and/or influence in the region could 

destabilize the very states the United States seeks to assure. Bunn raises 

the possibility that instead of deploying further U.S. military capabilities 

to the Middle East, the United States could provide conventional systems 

such as missile and air defense capabilities to its regional allies. 

The drawdown of nuclear weapons in pursuit of nuclear abolition will 

certainly have an effect on the United States’ ability to extend deterrence 

to friends and allies abroad. Bunn suggests that more effort needs to be 

put into studying the impact that the “three digit phase,” meaning 

hundreds of nuclear weapons, would have on the viability of extended 

deterrence and assurance.

353

 She speculates that during this phase 

numbers of warheads may become less important than postures of 

nuclear forces. Undoubtedly, when lower numbers are achieved, 

extended deterrence will become more complicated than it is today, and 
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it will likely become more difficult for the United States to credibly 

assure and deter.

Murdock, Clark, Exploring the Nuclear Posture Implications of 

Extended Deterrence and Assurance (Washington DC: Center for 

Strategic and International Studies, November 2009).

This CSIS report examines the credibility of U.S. extended 

nuclear deterrence from the perspectives of both the potential adversary 

(deteree), and the state protected by U.S. nuclear forces (assuree). The 

authors take a “credibility-centric approach” to assessing deterrence, 

maintaining that the credibility of both deterrence and extended 

deterrence depend on a range of factors which affect adversary 

perceptions of U.S. capabilities and intentions.354 The authors maintain 

that assurance will not work if the U.S. deterrent is not credible. 

However, a credible deterrent does not necessarily guarantee successful 

assurance. Three principle factors explain why the requirements for 

assurance and deterrence can differ. First, the degree to which assurance 

is affected by the elements of extended deterrence is dependent on how 

the ally perceives and interprets U.S. communications and actions 

regarding the deteree. Second, assurance, being a mutually beneficial 

relationship, requires participation and/or burden sharing in order to 

actively involve the ally. Third, the ally must have confidence in the 

long-term reliability of the U.S. nuclear deterrent. The authors state that 

the credibility of U.S. extended deterrence lies in the eyes of three 

beholders: allies and security partners, potential aggressors, and the 

American public. Assurance depends not just on what U.S. policy 

makers or experts determine is required for extended deterrence, but on 

what allies believe is required. The authors emphasize that 

comprehensive consultations with each security partner is essential for 

successful assurance. 

Payne, Keith. “How Much is Enough? A Goal-Driven Approach to 

Defining Key Principles,” National Institute for Public Policy (2009).

This article Keith Payne grapples with the question “how much 

is enough” in regard to U.S. nuclear capabilities. According to Payne, 

most contemporary claims that extended nuclear deterrence can be 

maintained with a fixed number of warheads are derived from an 

outdated Cold War-era formula for deterrence which assumed a known, 

predictable relationship between specific numbers and a desired 

deterrence effect. Payne offers that the contemporary threat environment 

is far more dynamic than that of the Cold War and, consequently, more 

factors must be taken into account when determining the appropriate 
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levels of strategic forces necessary for the United States to maintain an 

extended nuclear deterrent capable of both assuring allies and deterring 

adversaries. The lone threat of the Soviet Union during the Cold War 

has been replaced by a wide range of potential threats and diverse 

opponents. Since each threat is different and the strategic environment is 

continually subject to change, Payne maintains that there can be no 

reliable formula for determining what specific number of warheads, or 

what mix of capabilities, will be necessary to credibly maintain 

deterrence and extended deterrence in the future. Payne advises that U.S. 

deterrence plans and strategies should be flexible and able to adapt to an 

unpredictable and ever changing threat environment. “The diversity of 

opponents, circumstances and threats suggests that a contemporary 

deterrence priority is for a spectrum of U.S. forces options and flexibility 

of planning along with the traditional requirements for sufficient force 

quantity, lethality and survivability to threaten the array of targets 

deemed important for deterrence.”355 

Payne, Keith, “On Nuclear Deterrence and Assurance,” Strategic 

Studies Quarterly (Spring 2009).

In this Strategic Studies Quarterly article Keith Payne discusses 

the value of nuclear weapons for deterrence and assurance, the credibility 

of U.S. nuclear threats, and the resulting implications for the U.S. nuclear 

arsenal. Payne counters the arguments of contemporary commentators 

who assert that nuclear weapons have little or no value for deterrence 

given the technological advancement of nonnuclear capabilities. The 

current security environment dictates that U.S. leaders must work to 

deter a broad range of potential adversaries in varying situations. Given 

such complexity, wide-ranging U.S. strategic capabilities may be 

necessary. Payne points out that while nuclear weapons could be seen to 

have little value for combat missions, they remain essential for the 

deterrence of war and the assurance of allies. An adversary’s perception 

of the credibility of U.S. nuclear threats is vital to deterrence and U.S. 

observers cannot presume to understand the decision calculus of all 

potential adversaries. “To assert confidently that U.S. nuclear weapons 

no longer are valuable for deterrence purposes ... is to claim knowledge 

about how varied contemporary and future leaders in diverse and often 

unpredictable circumstances will interpret and respond to the distinction 

between nuclear and nonnuclear threats.”356 Similarly, assurance relies 

on each allies’ perception of U.S. credibility and dependability; allies 

themselves will determine if they are adequately assured. Payne argues 

that the credibility of U.S. nuclear threats is of paramount importance 

and suggests that accurate, low-yield nuclear weapons could create a 
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more “believable” deterrent threat. Further, Payne suggests that the size 

and character of the U.S. nuclear arsenal should be based on the 

following factors: the strategic threat environment, the relationship of the 

arsenal to other national goals (such as nonproliferation), the goals the 

arsenal is intended to serve (assurance and deterrence), potential 

contributions to these goals by other nonnuclear and nonmilitary means, 

and budget and technical realities. 

Pifer, Steven, Richard C. Bush, Vanda Felbab-Brown, Martin S. 

Indyk, Michael O’Hanlon and Kenneth M. Pollack. “U.S. Nuclear 

and Extended Deterrence: Considerations and Challenges,” 

Brookings, Arms Control Series Paper 3, May 2010.

This Brookings paper examines various considerations that 

policymakers in Washington must think about when considering how to 

maintain an effective nuclear deterrent. The main themes discussed 

include: deterrence in the nuclear age; the 2010 NPR’s conclusions, 

deterring a nuclear attack on the United States, U.S. declaratory policy, 

extended deterrence to regional allies; deterring chemical and biological 

weapons use, and deterring non-state actors. The following is a brief 

overview of the authors’ findings on extended deterrence.

Extended Deterrence and NATO Europe. Several challenges 

would be involved with any potential change to the United States’ 

extended deterrence policy to NATO. First, a change in the current 

policy could prompt individual nations to consider proliferation. Second, 

there is an active public debate in Europe regarding the presence of U.S. 

nuclear weapons in Europe, with several prominent statesmen calling for 

their removal. Third, there are differing views within Europe regarding 

the extent of the Russian threat. Some Western European allies discount 

the necessity of U.S. tactical nuclear weapons for deterring Russia, while 

various Eastern European allies have substantial concerns regarding 

potential Russian aggression and strongly prefer that U.S. nuclear 

weapons remain in the region. 

Extended Deterrence and East Asia. U.S. extended deterrence 

policy to East Asia is marked by a series of bilateral relationships and is 

dependent solely on U.S. strategic nuclear forces. Japan and South 

Korea are particularly concerned about the continued credibility of U.S. 

extended deterrence to the region. Japan, as well as Australia and 

Taiwan, are apprehensive of growing Chinese military power and 

influence in the region. South Korea is predominantly concerned about 

the North Korean nuclear program and how the United States is handling 

that situation. U.S. allies in East Asia will evaluate any alterations to 

U.S. extended deterrence policy in light of these circumstances. 
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Extended Deterrence and the Middle East. An Iranian 

acquisition of a nuclear weapons capability would greatly complicate the 

security situation in the Middle East and would amplify the importance 

of U.S. extended deterrence in the region. While the United States and 

the international community are working to dissuade Iran from 

developing nuclear weapons, it is uncertain if these efforts will succeed. 

As Iran approaches the nuclear weapons threshold, a main priority for the 

United States will be to discourage regional allies from taking unilateral 

measures to protect themselves, whether by preemptive military action or 

by further nuclear proliferation. 

Pilat, Joseph, “Nonproliferation, Arms Control and Disarmament, 

and Extended Deterrence in the New Security Environment,” 

Strategic Insights, September 2009.

In this Strategic Insights article Joseph Pilat makes the case that 

in the current security environment nuclear weapons remain important to 

the United States, although for a limited set of roles and missions. Pilat 

concedes that while the idea of a world free of nuclear weapons is 

enticing, the reality is that the danger and uncertainty which exist in 

global affairs make it unlikely that either current nuclear states or 

potential proliferators would be willing to completely forego nuclear 

weapons. Furthermore, a world without nuclear weapons would not 

necessarily be more secure or stable. Nonproliferation, arms control and 

disarmament goals should be pursued, but with the understanding that 

there is a continuing need for both deterrence and extended deterrence.

Pilat identifies four policy issues that could negatively affect 

extended deterrence in the near to medium term: non-strategic nuclear 

forces and the presence of U.S. nuclear weapons in Europe, ballistic 

missile defense, conventional capabilities, and reducing the role of 

nuclear weapons. If handled properly, none of these issues needs to have 

a negative impact on extended deterrence. However, Pilat maintains that 

“at some point along the path to a nuclear-weapon-free world ... the 

potential for the direct impact of reduced forces and capabilities on 

extended deterrence would be raised.”357 As the United States and others 

progress toward the goal of a nuclear-free-world, maintaining nuclear 

deterrence will be vital. The United States will need to work closely 

with its allies and proceed in a way that does not undermine deterrence. 

Pilat maintains that “deterrence offers order, stability and 

nonproliferation benefits along the path and it may even make the pursuit 

of the goal of a nuclear-weapon-free world more realistic.”358
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Russell, James, “Extended Deterrence, Security Guarantees, and 

Nuclear Weapons,” in Bruno Tertrais, ed, Perspectives on Extended 

Deterrence, (Paris: Fondation pour la Recherché Strategique, Recherches 

et documents no.3), March 2010.

In the sixth chapter of Perspectives on Extended Deterrence

James Russell addresses security guarantees, the role of nuclear 

weapons, and challenges facing policy makers regarding America’s 

security strategy in the Middle East. Russell notes that, historically, 

nuclear weapons have both implicitly and explicitly helped to support 

U.S. global commitments in the Middle East and elsewhere. The United 

States has shown its willingness to deploy conventional forces in 

response to instability in the Middle East many times since the British 

withdrew from the region in the early 1970s. After the conclusion of 

Operation Desert Storm, the United States further demonstrated its 

commitment to the region by concluding bilateral defense cooperation 

agreements with nearly all of the states in the Middle East. The United 

States has made no explicit nuclear guarantees to any states in the region, 

however, nuclear weapons are explicitly committed to the defense of 

American forces anywhere in the world whenever the president of the 

United States considerers it necessary. Russell states that “in the Gulf, 

the dual tools of extended deterrence and security assurances have 

proven a cornerstone of a system of regional security efficiently 

administered by America’s military organizations. Nuclear weapons 

undeniably form a part of this system – explicitly protecting US forces 

and implicitly protecting the regimes hosting those forces.”359 

Russell also addresses policy challenges and inconsistencies 

which he hoped would be addressed in the 2010 Nuclear Posture Review. 

He asserts that nuclear disarmament and extended deterrence 

commitments are incompatible. “Actively promoting nuclear 

disarmament on the one hand while also drawing upon nuclear weapons 

on the other to prevent a regional arms race in the Gulf is a contradiction 

that must be addressed by the NPR drafters.”360 Russell also warns that 

the United States’ strategic nuclear arsenal could become a “wasting 

asset” as the weapons themselves age and the human and material 

infrastructure become more difficult to maintain. He claims that the 

United States is slowly disarming itself and, if current trends continue, 

sooner or later there will come a time when the United States will be 

unable to credibly back its extended deterrence commitments. 

Schneider, Mark, “The Future of the US Nuclear Deterrent,” 

Comparative Strategy, Vol. 27, Issue 4, 2008.
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In this Comparative Strategy article Mark Schneider points out 

that the United States is the only nuclear-weapons state that is not 

modernizing its nuclear deterrent and is, in fact, debating whether it 

should retain its nuclear deterrent at all. Every other nuclear-weapons 

state is committed to maintaining and modernizing its nuclear deterrent. 

Schneider identifies a number of states that he claims represent “actual 

existing threats to the survival of the United States,”361 including: Russia, 

China, North Korea, Iran and Syria. He maintains that a reliable nuclear 

deterrent is necessary to address imminent threats to the continued 

existence of the United States. While Schneider acknowledges that 

missile defenses and conventional strike capabilities are critical elements 

of deterrence and national power, he is adamant that they cannot 

substitute for nuclear weapons. He further avows that U.S. nuclear 

forces must be modernized and adapted to enhance deterrence. 

Schoff, James, “Does the Nonproliferation Tail Wag the Deterrence 

Dog?” PacNet 9, CSIS, 5 February 2009.

James Schoff emphasizes the importance of keeping the broad 

picture in mind when formulating U.S. nuclear policy in the 21st century. 

Prior to the release of the 2010 NPR numerous studies were published 

which focused on the role of U.S. nuclear forces. Many of these studies 

underscored the vital role that U.S. nuclear forces play in bolstering 

extended deterrence and reassuring allies, but some studies called for 

nonproliferation measures which, in Schoff’s opinion, could potentially 

weaken extended deterrence. Focusing on the viewpoints of Japan and 

South Korea, Schoff stresses that it is essential to be mindful of how U.S. 

nuclear policy decisions are perceived by allied nations. Care must be 

taken to balance discussions of arms control and reducing the role of 

U.S. nuclear forces with credible assurances of the United States’ 

dedication to maintaining its extended deterrence commitments to 

nations like Japan and South Korea. Schoff asserts that “policy makers 

must recognize the interwoven nature of the nuclear umbrella, extended 

deterrence, and the broader alliance relationships.”362 One aspect of 

nuclear policy cannot be altered without affecting the others. 

Tertrais, Bruno “Security Guarantees and Extended Deterrence in 

the Gulf Region: A European Perspective,” Strategic Insights, Vol. 

VIII, Issue 5, December 2009.

In this Strategic Insights article Bruno Tertrais discusses the 

prospects for extended deterrence in the Gulf region. While the United 

States currently provides security to the region, it does so in a manner 

distinctly different from the extended deterrence models associated with 
157

Europe and East Asia. There are no explicit treaty-based guarantees in 

the Gulf region; instead a number of unilateral and bilateral security 

agreements have been established between the United States and 

individual Gulf states. Tertrais states that debate surrounding U.S. 

extended deterrence to the Gulf has been renewed in recent years due to 

two factors: the so-called “Shi’a revival” and the growing controversy 

regarding Iranian nuclear intentions.363 There is concern that if allies in 

the region are not adequately assured that their security is guaranteed, 

some may seek alternative means to safeguard their security. For 

example, there is speculation that Saudi Arabia could seek either a 

national nuclear option or a nuclear guarantee from Pakistan in the event 

that an Iranian nuclear weapon was developed.

Tertrais identifies specific challenges to extending deterrence to 

the Gulf. One challenge is that neither the United States nor its regional 

allies wish to appear as if they’ve accepted the eventuality of an Iranian 

nuclear capability. Another is that leaders of many Gulf states do not 

want to explicitly advertise their security arrangements with the United 

States, but prefer to keep such arrangements ambiguous. Tertrais 

demonstrates the complexity of the situation by stating that “in the Gulf 

region, extended deterrence is a particularly acute challenge, where it 

will be particularly difficult to simultaneously satisfy the requirements of 

‘deterrence’ (vis-à-vis potential adversaries), ‘reassurance’ (vis-à-vis 

friendly governments), and ‘acceptability’ (vis-à-vis their public 

opinions).”364

Certain European countries, particularly France and the United 

Kingdom, have concluded their own security agreements with states in 

the Gulf region. Interestingly, regional perceptions of French and UK 

security engagements do not involve the kinds of negative connotations 

that are associated with those involving the United States. Tertrais 

maintains that French and UK extended deterrence postures to the region 

complement that of the United States and suggests that trilateral 

consultation could be valuable in order to better coordinate the roles of 

each nation would play in the event of a regional conflict or crisis.

Tertrais, Bruno, “The Future of Extended Deterrence: A 

Brainstorming Paper,” in Perspectives on Extended Deterrence, 

(Paris: Fondation pour la Recherché Strategique, Recherches et 

documents no.3), March 2010.

In the first chapter of Perspectives on Extended Deterrence

Bruno Tertrais provides an overview of the concept of extended 

deterrence, examines the role of security guarantees in nuclear nonproliferation, and identifies some problems and dilemmas associated 
158

with reinforcing security guarantees. Extended deterrence commitments 

can take a number of forms ranging from unilateral statements promising 

protection to physical placement of nuclear weapons on a protected 

country’s territory. Effective extended deterrence involves both 

deterring potential aggressors and assuring allies; the requirements for 

“deterrence” and “assurance” are not identical and finding the right 

balance between the two can be challenging. A benefit of providing 

allies with strong security guarantees is that the non-proliferation regime 

is strengthened as a result. The discussion on how to best implement 

extended deterrence is evolving and some topics which complicate the 

debate include developments in missile defense and conventional 

precision strike technologies, efforts to reduce the role of nuclear 

weapons in defense postures, consideration of “no-first-use” doctrines, 

the nuclear abolition movement, and the credibility of deterrence against 

unconventional threats such as terrorism and cyber warfare. 

Providing security guarantees to allies can also produce a 

number of problems. One risk is that the protected state may choose to 

reduce their conventional defense capabilities making them more 

dependent on foreign protection and putting the protector state at risk of 

entanglement. Another risk is that states covered by security guarantees 

could become “emboldened to embark in dangerous adventures.”365

Further, friends or partners who are not covered by security guarantees 

could be tempted to seek their own nuclear capabilities. Often, effective 

deterrence hinges on the principle of ambiguity; strong, explicit security 

guarantees run counter to this principle. In some regions, such as the 

Middle East, explicit security guarantees can create political issues for 

the governments of the protected state as well as for the United States. 

Another possible risk of strong security guarantees is that they could 

provide adversarial states with a motive to proliferate. Finally, providing 

security guarantees to multiple allies may increase the risk that 

eventually one of those guarantees might be seriously tested during a 

crisis or conflict. 

Trachtenberg, David, “U.S. Extended Deterrence: How Much 

Strategic Force is Too Little?” Strategic Studies Quarterly, Summer 

2012. 

In this Strategic Studies Quarterly article David Trachtenberg 

discusses the history of extended deterrence, the relationship between 

extended deterrence and nonproliferation, the role of strategic and 

nonstrategic nuclear forces in extended deterrence, extended deterrence 

by other means (including third party nuclear capabilities, nonnuclear 

capabilities, and missile defense), allied views of assurance, the 
159

robustness of the U.S. nuclear enterprise, the impact of the Obama 

administration’s nuclear policies, and the significance of force structure 

as numbers of nuclear weapons decrease.

Trachtenberg alleges that the United States is on the cusp of 

what he describes as the “third atomic age,” an era in which the role of 

nuclear weapons in U.S. national security strategy is diminishing and the 

nuclear forces supporting that strategy are being reduced to historically 

low levels.366 The requirements for assurance and extended deterrence 

are not one and the same; the appropriate numbers and force postures 

depend on the perceptions of both allies and adversaries. The continued 

viability of the U.S. nuclear weapons complex is crucial for the future 

credibility of extended nuclear deterrence; in fact, it may be even more 

relevant to some European allies than the levels or composition of U.S. 

nuclear forces. While conventional weapons and missile defenses may 

enhance extended deterrence, Trachtenberg contends that they will not be 

sufficient to replace nuclear weapons altogether. Trachtenberg also 

states that American views of how others should perceive the credibility 

of U.S. nuclear threats are less relevant than how those threats are 

actually perceived. Ultimately, the success of extended deterrence will 

be determined by the extent to which both allies and adversaries perceive 

U.S. commitments to be credible. Consequently, future decisions 

regarding U.S. nuclear forces should be preceded by comprehensive 

consultations with the friends and allies who stake their security on the 

reliability of U.S. extended nuclear deterrence. 

Wheeler, Michael, The Changing Requirements of Assurance and 

Extended Deterrence, Institute for Defense Analyses, July 2010.

This Institute for Defense Analyses paper is based on discussions 

which took place during a series of workshops conducted to examine 

U.S. assurance and extended deterrence strategies and their requirements. 

These workshops brought deterrence experts and regional specialists 

together to discuss what requirements, if any, are changing for security 

assurances and extended deterrence in three regions: Europe, the Middle 

East, and the Asia Pacific. 

While each region requires different assurance strategies, 

analysis of the workshops resulted in four general conclusions. First, 

although the underlying principles of extending nuclear deterrence have 

not changed significantly, the United States should pay greater attention 

to adjusting its engagement strategies with security partners to ensure 

that assurances remain strong and positive. Second, the United States’ 

ability to extend deterrence is greater than just the nuclear component; it 

also includes conventional forces and missile defense. Third, the 
160

prospect for success of U.S. assurances often depends as much on its 

ability to conduct successful campaigns of coercive diplomacy as it does 

on traditional deterrence practices. Fourth, the prospect for success of 

U.S. security assurances cannot be separated from wider perceptions of 

the United States’ relative power in the world. 

Some of the enduring requirements identified in the analysis 

include the importance of managing expectations regarding the nature of 

assurance relationships, understanding the enduring features of 

deterrence, and adapting to evolving security environments. New and 

changing requirements include the increasing importance of missile 

defenses for dealing with states such as North Korea and Iran, 

reinvigorating NATO nuclear defense consultations to address the 

current security environment, finding new approaches for deeper defense 

consultations with partners such as Japan and South Korea, and the 

development of a new framework for stability analysis which would 

account for the complex interplay between the strategies of coercive 

diplomacy and deterrence.

Yost, David, “Assurance and US Extended Deterrence in NATO,” 

International Affairs, Vol. 85, Issue 4, July 2009.

In this International Affairs article David Yost discusses the 

historical and current assurance roles of U.S. nuclear forces in Europe, 

paying particular attention to the elements of assurance related to U.S. 

extended nuclear deterrence in NATO. The specific roles of U.S. nuclear 

forces in Europe identified by Yost include serving as a hedge against 

Russian recidivism, deterring regional powers armed with WMD, 

providing an alternative to considering dependence on French and/or 

British nuclear forces, offering an alternative to the pursuit of national 

nuclear forces, and supplying evidence of the genuineness of U.S. 

commitments.367 Yost identifies the key elements of assurance and

extended deterrence in NATO as widespread allied confidence in the 

reliability of the United States, the openness of the United States to allied 

influence, the U.S. military presence in Europe, the U.S. nuclear 

weapons presence in Europe as a link to U.S. strategic nuclear forces, 

allied roles in the nuclear posture, and an agreed strategic policy. 

Further, Yost discusses three factors which he suggests may make 

reaching a consensus during the (then) upcoming NATO Strategic 

Concept review particularly challenging. Those factors include the arms 

control context, divisions in both public and expert opinion within 

NATO countries, and concerns regarding the possible consequences of a 

break from the established arrangements for the sharing of nuclear risks 

and responsibilities. 
161

NOTES

 

1 Elaine Bunn, “The Future of U.S. Extended Deterrence,” in Perspectives on 

Extended Deterrence (Fondation pour la Recherche Strategique, Recherches et 

documents no. 3, 2010), 35 (emphases in original).

2 Department of Defense, Department of Defense Dictionary of Military and 

Associated Terms, Joint Publication 1-02 (Washington D.C., 2011), 107.

3 Department of Defense, Deterrence Operations Joint Operating Concept, 

version 2 (Washington D.C., 2006), 3.

4 Department of Defense, “Sustaining U.S. Global Leadership: Priorities for 21st

Century Defense” (Washington D.C., January 2012), 4 (emphasis in original) 

[hereafter 2012 DSG].

5 During the Cold War, “deterrence” was often used as shorthand for “nuclear 

deterrence,” reflecting the critical importance of nuclear weapons, and efforts to 

deter nuclear attack, to the strategic thinking of this era. This practice still 

persists decades after the end of the U.S.-USSR superpower rivalry despite 

efforts by USSTRATCOM and others to broaden concepts and discussions of 

deterrence to include other military capabilities such as space assets, missile 

defenses, and niche capabilities. General Kevin Chilton and Greg Weaver, 

“Waging Deterrence in the Twenty-first Century,” Strategic Studies Quarterly

(Spring 2009), 37-41, and Department of Defense, Ballistic Missile Defense 

Review Report (Washington D.C., February 2010), 6-7.

6 Kenneth Watman et al., “U.S. Regional Deterrence Strategies,” RAND 

Corporation report (Santa Monica, CA: RAND, 1994), 15. 

7

Steven Pifer, Richard C. Bush, Vanda Felbab-Brown, Martin S. Indyk, 

Michael O. Hanlon, and Kenneth M. Pollack, U.S. Nuclear and Extended 

Deterrence, Brookings Arms Control Series, Paper No. 3 (Washington, D.C.: 

Brookings, May 2010), 1. The authors of the 2010 Brookings Institution report 

“U.S. Nuclear and Extended Deterrence,” for example, note that the United 

States sought to deter the Soviet Union from attacking Iran in 1979. Following 

the Soviet Union’s invasion of Afghanistan, the United States was determined to 

extend deterrence to protect Iran (and, more broadly, the strategically vital 

Persian Gulf), despite a recent revolution toppling a friendly regime and 

bringing a virulently anti-U.S. government to power in Tehran. 

8

Jeffrey Larsen, Justin Anderson, Darci Bloyer, Thomas Devine, Rebecca 

Gibbons, and Christina Vaughan. Qualitative Considerations of Nuclear 

Weapons at Lower Numbers and Implications for Future Arms Control 

Negotiations, Air Force Institute for National Security Studies Occasional Paper 

68 (July 2012), xii-xiii.

9 Clark Murdock et al. Exploring the Nuclear Posture Implications of Extended 

Deterrence and Assurance (CSIS: Washington D.C., November 2009), 1.
162

 

10 Chilton and Weaver, “Waging Deterrence in the Twenty-first Century,” 34-

35, and Michael O. Wheeler, “The Changing Requirements of Assurance and 

Extended Deterrence,” IDA Paper P-4562 (Alexandria, VA: Institute for 

Defense Analysis, July 2010), iii-iv.

11 For example, during a May 2012 commencement address delivered at the U.S. 

Air Force Academy, President Obama included one reference to the Democratic 

People’s Republic of Korea (DPRK) within remarks addressing a range of 

national security and foreign affairs topics (stating the country “cannot be 

allowed to threaten the world with nuclear weapons”). Two weeks later, the 

DPRK government’s official news agency issued a press release quoting the 

address and referring to Obama’s mention of the DPRK’s nuclear weapons 

program “as revelation of the U.S. foolish design to stir up atmosphere hostile to 

the DPRK and justify the modernization of its nuclear weapons under the pretext 

of non-existent ‘nuclear threat’ from someone.” White House Office of the Press 

Secretary, “Remarks by the President at the Air Force Academy 

Commencement,” address transcript, U.S. Air Force Academy, May 23, 2012, 

and Korean Central News Agency, “KCNA Slams US Foolish Moves to Justify 

Its Modernization of Nukes,” June 6, 2012.

12 Conversely, the failure of U.S. leaders or officials to state express security 

guarantees can leave allies and partners vulnerable to foreign interference. In 

January 1950, Secretary of State Dean Acheson gave a speech on U.S. security 

guarantees in Asia, describing a defense perimeter that included Japan but not 

South Korea. In June 1950, North Korea launched a major invasion of the 

South. Although historians have found no definitive link between the two 

events, many believe Acheson’s statement – and the national security policy it 

reflected – led Soviet and North Korean leaders to believe that the United States 

would not militarily intervene on behalf of South Korea. Max Hastings, The 

Korean War (New York: Simon and Schuster, 1987), 57-58, and Seung-young 

Kim, American Diplomacy toward Korea and Northeast Asia, 1882-1950 (New 

York: Palgrave Macmillan, 2009), 187.

13 In President Reagan’s 1982 State of the Union address, for example, he 

emphasized the importance of America’s long-standing alliances and warned the 

Soviet Union that the United States would counter any effort to expand the 

Communist bloc: “We have not neglected to strengthen our traditional alliances 

in Europe and Asia, or to develop key relationships with our partners in the 

Middle East and other countries ... When radical forces threaten our friends, 

when economic misfortune creates conditions of instability, when strategically 

vital parts of the world fall under the shadow of Soviet power, our response can 

make the difference between peaceful change or disorder and violence.” 

President Ronald Reagan, State of the Union Address, Joint Session of 

Congress, Washington D.C., January 26, 1982. Similarly, President Clinton’s 

1998 State of the Union address included messages intended to deter potential 

adversaries and assure U.S. allies and partners. President Clinton warned Iraqi 

dictator Saddam Hussein not to contemplate use of WMD (“I know I speak for 
163

 

everyone in this chamber, Republicans and Democrats, when I say to Saddam 

Hussein: You cannot defy the will of the world. And when I say to him: You 

have used weapons of mass destruction before. We are determined to deny you 

the capacity to use them again.”) and pledged to support U.S. allies and partners 

abroad (“In the months ahead, I will pursue our security strategy with old allies 

in Asia and Europe, and new partners from Africa to India and Pakistan, from 

South America to China. And from Belfast to Korea to the Middle East, 

America will continue to stand with those who stand for peace.)” President 

William J. Clinton, State of the Union Address, Joint Session of Congress, 

Washington D.C., January 27, 1998.

14 Keith Payne, Thomas Scheber, and Kurt Guthe. U.S. Extended Deterrence 

and Assurance for Allies in Northeast Asia, National Institute for Public Policy 

(NIPP) report (Fairfax, VA: NIPP, March 2010), 9-11. 

15 The experts examined the salvaged wreckage of the Cheonan and pieces of a 

foreign torpedo that was also discovered at the site. They concluded the ship 

was sunk due to a surprise torpedo attack launched by a nearby submarine. 

Investigators found a Korean character on one of the recovered pieces of the 

torpedo and also concluded it matched the design and specifications of a weapon 

known to be manufactured by the DPRK. In addition, at the time of the attack 

ROK intelligence was aware of the presence of DPRK submarines in the vicinity 

of the Cheonan. Joint Civil-Military Investigation Group, Investigation Result 

on the Sinking of the ROKS “Cheonan,” May 20, 2010, and Ambassador Han 

Duk-Soo, “The Cheonan Situation,” briefing, CSIS, Washington D.C., May 25, 

2010.

16 White House Office of the Press Secretary, “Statement by the Press Secretary 

on the Republic of Korea,” press release, May 24, 2010.

17 Embassy of the United States-Korea, “Press Conference with President 

Obama and President Lee Myung-bak,” event transcript, November 11, 2010. 

18 Chinese foreign policy and national security experts, for example, have 

closely read U.S. national strategic guidance documents since the mid-1990s. 

Jin Carong, “The US Global Strategy in the Post-Cold War Era and its 

Implications for China-United States Relations: a Chinese Perspective,” Journal 

of Contemporary China 10, no. 27 (2001), 309-315; Colonel Yunzhu Yao, “A 

Chinese Perspective on the Nuclear Posture Review,” Carnegie Proliferation 

Analysis, May 6, 2010; and Lora Saalman, China and the U.S. Nuclear Posture 

Review, Carnegie Endowment for International Peace (CEIP) Paper 

(Washington D.C.: CEIP, February 2011), 4-13.

19 Gary L. Guertner, “European Views of Preemption in US National Security 

Strategy,” Parameters (Summer 2007), 33-37; Scott Snyder, “Finding a Balance 

Between Assurances and Abolition: South Korea Views of the NPR,” The 

Nonproliferation Review 18, No. 1 (March 2011), 150-154, and; Lewis Dunn, 

Greg Giles, Jeffrey Larsen, and Thomas Skypec, “Foreign Perspectives on U.S. 
164

 

Nuclear Policy and Posture: Insights, Issues, and Implications,” Defense Threat 

Reduction Agency (DTRA) report (December 12, 2006), 250-255. 

20 White House, National Security Strategy 1990 (Washington D.C.: March 

1990), 9. 

21 Ibid, 12.

22 White House, National Security Strategy (Washington D.C.: May 2010), 41 

[hereafter 2010 NSS].

23 2010 DSG, 2 (emphasis in original). 

24 Ibid. 

25 Department of Defense, Nuclear Posture Review Report (Washington D.C., 

April 2010), xi [hereafter 2010 NPR]. The 2010 Nuclear Posture Review Report

states “[t]he United States will continue to ensure that, in the calculations of any 

potential opponent, the perceived gains of attacking the United States or its 

allies and partners [with nuclear weapons] would be far outweighed by the 

unacceptable costs of the response.” 

26 Richard Estes, “The Role of Strategic Communication Deterrence: Lesson 

from History,” Chap. 12 in Schneider, Barry and Patrick Ellis, eds, Tailored 

Deterrence: Influencing States and Groups of Concern, (Maxwell, AL: Air 

Force Counterproliferation Center, 2011), 351-352.

27 Lawrence Freedman, The Evolution of Nuclear Strategy, 3rd ed. (New York: 

Palgrave Macmillan, 2003), 296.

28 Underlying ROK concerns regarding the continued U.S. commitment to their 

security in the face of a nuclear-armed DPRK prompted a request during highlevel U.S.-ROK meetings in 2009 for an express statement of the U.S. nuclear 

extended deterrence commitment. The United States agreed, and the two 

government’s 2009 “Joint Vision for the Alliance” states “[t]he continuing 

commitment of extended deterrence, including the U.S. nuclear umbrella, 

reinforces [U.S.] assurance [guarantees to the ROK].” White House Office of 

the Press Secretary, “Joint Vision for the Alliance of the United States of 

America and the Republic of Korea,” press release, June 16, 2009, and Pifer et 

al., U.S. Nuclear and Extended Deterrence, 31-32. 

29 In 1954, Secretary of State John Foster Dulles articulated a strategy of 

“massive retaliation” to address this imbalance by threatening to use nuclear 

weapons in response to a conventional attack on NATO: “Local defenses must 

be reinforced by the further deterrent of massive retaliatory power .... 

Otherwise, for example, a potential aggressor, who is glutted with manpower, 

might be attempted to attack in confidence that resistance might be confined to 

manpower.” John Foster Dulles, address, Council on Foreign Relations, 

Washington D.C. January 12, 1954 in Cynthia Ann Watson, U.S. National 
165

 

Security: A Reference Handbook (ABC-Clio, Inc: Santa Barbara, CA 2002), 

163-164.

30 2010 NPR, 17.

31 Ibid, 16.

32 Ibid, 16.

33 Ibid, 17.

34 Ibid, 16. 

35 Embassy of the Republic of Korea in the USA, “The ROK-U.S. Mutual 

Defense Treaty,” n.d.

36 Article V, United States, “North Atlantic Treaty,” in Bevans, Charles I. ed. 

Treaties and Other International Agreements of the United States of America, 

1776-1949, vol. IV (Washington D.C.: Department of State, 1968), 829.

37 Yukio Satoh, “Are the Requirements for Extended Deterrence Changing?” 

Carnegie International Nonproliferation Conference panel transcript, 

Washington D.C., April 6, 2009. 

38 Chilton and Weaver, “Waging Deterrence,” 36. 

39 Department of Defense, Office of the Assistant Secretary of Defense (Public 

Affairs), “DoD News Briefing with Secretary Gates and Republic of Korea 

Defense Minister Kim,” press transcript, October 8, 2010. 

40 Jim Garamone, “U.S.-South Korea Alliance Remains Strong, Leaders Say,” 

American Forces Press Service, October 8, 2010.

41 U.S.-ROK Security Consultative Meeting, “U.S.-ROK Security Consultative 

Joint Communique,” 43rd U.S.-ROK Security Consultative Meeting, Seoul, 

Republic of Korea, October 28, 2011.

42 During a joint exercise between the United States and Japan titled “Keen 

Sword,” Admiral Umio Otsuka of Japan’s Self Defense Force noted its value for 

improving the ability of the two armed forces to operate as one cohesive entity: 

“We have already gained ground in terms of increasing our interoperability .... 

This exercise does a good job of preparing us to work as one entity although we 

are two individual nations.” Mass Communications Specialist Juan Pinalez, 

“Keen Sword 2011 Brings US and Japanese Sailors Together,” U.S. Navy press 

release, December 6, 2010.

43 Many allies and partners echo views expressed by Major General Arvydas 

Pocius, Lithuania’s Defence Minister, following his observation of a joint 

exercise conducted by the United States and its three Baltic NATO allies: 

“‘This training event is based on one of NATO's underlying principles: one for 

all and all for one, when you come together and stand shoulder to shoulder, and 

here we are - the three Baltic States and USA’ ... [in further remarks he] 
166

 

stressed that the exercise was a great proof of successful strategic partnership 

between the United States and the Baltic States.” Lithuania Ministry of National 

Defense, Lithuania Armed Forces, “Chief of Defense of Lithuania Observed 

Joint Training of Baltic and US Troops,” press release, October 22, 2010. 

44 Jim Garamone, “U.S., Korean Defense Leaders Announce Exercise Invincible 

Spirit,” American Forces Press Service, July 20, 2010. 

45 Mass Communications Specialist 1st Class Ernesto Bonilla, “U.S. Navy EOD 

Unit Shares Training, Fosters International Partnerships,” U.S. Navy Region 

Hawaii press release, July 19, 2012.

46 Ibid. 

47 Bonilla, “U.S. Navy EOD Unit”; Mass Communications Specialist 2nd Class 

Philip Pavlovich, “Sea Spirit at RIMPAC,” U.S. Navy press release, July 21, 

2012; and William Cole, “RIMPAC Vessels Head Out to Sea for War Games,” 

Honolulu Star-Advertiser, July 11, 2012. 

48 Department of Defense, Quadrennial Defense Review (Washington D.C., 

February 2010), 63 [hereafter 2010 QDR].

49 After conducting research interviews with government officials and subject 

matter experts from the Eastern European members of NATO considering 

possibly hosting components of a U.S./NATO missile defense system –

components guarded and/or supported by U.S. conventional forces, Polish 

defense analyst Lukasz Kulesa concluded “[t]he deployment of the US 

conventional military forces to the region was seen as the most credible backup 

of the US security assurances.” Kulesa found that countries such as the Czech 

Republic and Poland subsequently offered to host U.S./NATO missile defense 

systems largely because “the crucial importance of the planned installations for 

the security of the United States ... would guarantee Washington involvement in 

the affairs of the region.” Lukasz Kulesa, “Extended Deterrence and Assurance 

in Central Europe,” in Perspectives on Extended Deterrence (Fondation pour la 

Recherche Strategique, Recherches et documents no. 3, 2010), 122.

50 Japan, for example, provided $2.3 billion in host-nation support funds in 

2012. David J. Berteau and Michael J. Green, dirs, U.S. Force Posture Strategy 

in the Asia-Pacific Region: An Independent Assessment (Washington D.C.: 

Center for Strategic and International Studies, August 2012), 18. 

51 Donna Miles, “Obama Announces Expanded U.S. Military Presence in 

Australia,” American Forces Press Service, November 16, 2011.

52 Office of the Prime Minister of Australia, “Transcript of Press Conference, 

Bali,” press release, November 19, 2011. 

53 2010 QDR, 31.

54 Ibid, 1, 32-33, 103. 
167

 

55 DSG, 3.

56 The 2010 NPR stated that nuclear forces remained essential to extended 

deterrence and assurance strategies but that the United States would “reduce the 

role and numbers” of its nuclear arsenal. 2010 NPR, v. 

57 For example, the recent change to U.S. declaratory policy regarding potential 

biological or chemical weapon attacks conducted against the United States by a 

non-nuclear adversary rules out the use of a nuclear weapon in response, stating 

the United States will instead elect to use a “devastating conventional response.” 

2010 NPR, viii. 

58 Major Wade S. Karren, “Long Range Strike: The Bedrock of Deterrence and 

America’s Strategic Advantage,” Air and Space Power Journal (May-June 

2012), 75. 

59 Jeremiah Gertler, Operation Odyssey Dawn (Libya): Background and Issues 

for Congress, Congressional Research Service (CRS) report, March 28, 2011, 

10-11. 

60 2010 QDR, iv. 

61 Significantly, several prominent Russian national security analysts assert that 

advanced conventional weapon capabilities are now considered a greater threat 

than missile defenses or certain nuclear capabilities: “long-range high precision 

weapons [represent] a new destabilizing factor of greater importance than 

missile defense, TNW [tactical nuclear weapons] and the US upload hedge in 

strategic offensive weapons.” Alexei Arbatov, Vladamir Dvorkin, and Sergey 

Oznobishchev, Russia and the Dilemmas of Nuclear Disarmament (Moscow: 

Institute of World Economy and International Relations/Nuclear Threat 

Initiative, 2012), 26. 

62 Thom Shanker, Eric Schmitt, and David E. Sanger, “U.S. Adds Forces in the 

Persian Gulf, a Signal to Iran,” New York Times, July 3, 2012.

63 2010 NPR, 1, 15-17.

64 Ibid, 30. 

65 2010 NPR, 24.

66 Keith B. Payne, “On Nuclear Deterrence and Assurance,” Strategic Studies 

Quarterly 3, No. 1 (Spring 2009), 56. 

67 Congressional Commission on the Strategic Posture of the United States, 

America’s Strategic Posture (Washington D.C.: United States Institute for Peace 

Press, 2009), 61, and Victor Utgoff and David Adesnik, “On Strengthening and 

Expanding the U.S. Nuclear Umbrella to Dissuade Nuclear Proliferation,” IDA 

report (Alexandria, VA: IDA, July 2008), 13-16.
168

 

68 As noted by Japanese national security expert Ken Jimbo, “Ensuring the 

visibility of U.S. nuclear commitment in Asia is still important ... it could be 

flexibly forward-deployed, especially by the air component.” Ken Jimbo, 

“Extended Deterrence and the 21st Century,” Carnegie International Nuclear 

Policy Conference panel transcript, March 2011. See also David Yost, 

“Assurance and US Extended Deterrence in NATO,” International Affairs vol. 

85, No. 4 (2009), 764.

69 As noted by General Gary L. North, commander of Pacific Air Forces, in 

response to a reporter writing a story on “continuous presence:” "Both our 

friends and adversaries are very aware of the force structure laydown in the 

Pacific.” Rebecca Grant, “Bomber Diplomacy,” Air Force Magazine

(December 2011).

70 Benjamin Stratton, “B-52s Head to Guam for Continuous Bomber Presence 

Rotation,” Air Force press release, June 3, 2010. 

71 The role played by the Patriots in the 1991 Gulf War is important for 

understanding the mechanics of assurance. Both prior to and during the conflict, 

allies and partners believed the high-tech systems could effectively defend them 

against ballistic missile attack. As a result, they provided a degree of assurance 

to allies and partners throughout the conflict, even as the system’s actual 

battlefield performance fell short of U.S. expectations. Kenneth P. Werrell, 

Archie to SAM: A Short Operational History of Ground-based Air Defense

(Maxwell, AL: Air University Press, 2005), 204-208, and Steven A. Hildreth, 

“Evaluation of U.S. Army Assessment of Patriot Anti-tactical Missile 

Effectiveness in the War Against Iraq,” report for House Government 

Operations Subcommittee on Legislation and National Security, April 7, 1992. 

72 Department of Defense, Ballistic Missile Defense Review Report (Washington 

D.C., February 2010), 4-9 [hereafter 2010 BMDR]. 

73 Ibid, 12. 

74 Japan lodged formal diplomatic complaints with the DPRK following tests 

conducted in April and July 2009. Sent via China – Japan and the DPRK do not 

have direct diplomatic relations – the April demarche states the test represents “a 

threat to the peace and stability of the region, and directly impacts the security 

of Japan.” The Japanese message after the second test went a step further, 

stating the DPRK’s actions represented “grave and provocative” acts. Ministry 

of Foreign Affairs of Japan, “Japan Protests the Launch of Flying Object by 

North Korea,” press release, April 5, 2009, and “Japan Protests Against North 

Korea’s Missile Launches,” press release, July 4, 2009. 

75 Ministry of Foreign Affairs of Japan, “Deployment of US PAC-3 to Kadena,” 

press release, July 20, 2006.
169

 

76 Missile Defense Agency, “Joint Japan-U.S. Missile Defense Test Successful,” 

press release, October 29, 2010, and Ronald O’Rourke, Sea-based Ballistic 

Missile Defense: Issues for Congress, CRS Report, May 21, 2009, 8.

77 Missile Defense Agency, “Elements: Aegis Ballistic Missile Defense,” n.d. 

78 Ministry of Foreign Affairs of Japan, “Deployment of US PAC-3 to Kadena,” 

and Karen Parrish, “U.S., Japan Begin Coordination of Second Radar 

Installation,” American Forces Press Service, September 17, 2012. 

79 Ogawa Shinichi, “Missile Defense and Deterrence,” National Institute for 

Defense Studies (NIDS) report (Tokyo, Japan: NIDS, 2001), 32-33.

80 Saki Dockrill, Eisenhower’s New Look National Security Policy, 1953-1961

(London: Macmillan Press, 1996), p. 29, and Robert R. Bowie and Richard H. 

Immerman, Waging Peace: How Eisenhower Shaped an Enduring Cold War 

Strategy (Oxford: Oxford University Press, 1998), 98.

81 State Department, Foreign Relations of the United States, 1952-1954, Vol. II, 

582. 

82 “By the close of 1953, SAC had fully equipped 11 of the 17 wings in the 

atomic strike force. The bomber force included 329 B-47s and 185 B-36s. These 

aircraft were supported by 137 RB-136s, 500 tankers, and more than 200 

fighters. Strategic Air Command personnel numbered almost 160,000 at 29 

Stateside and 10 overseas bases.” Herman S. Wolk, “The ‘New Look,’” Air 

Force Magazine (August 2003). 

83 Lt Gen James Edmundson, “Race for the Superbomb,” The American 

Experience (web site), interview transcript, 1999. 

84 John Foster Dulles, address, Council on Foreign Relations, January 12, 1954 

in Cynthia Ann Watson, U.S. National Security: A Reference Handbook (ABCClio, Inc: Santa Barbara, CA 2002), 163-164.

85 Freedman, The Evolution of Nuclear Strategy, 82.

86 Mary M. Simpson, “News and Notes,” Bulletin of the Atomic Scientists

(February 1, 1954), 58.

87 Ibid, 85.

88 In 1958-59, for example, the United States began deploying nuclear cannons, 

rockets, and medium-range missiles to the ROK. The deployment was a direct 

response to concerns that the ROK leadership required some form of 

reassurance to address drawdowns in U.S. conventional forces on the Korean 

Peninsula. Michael Gordon Jackson, “Beyond Brinkmanship: Eisenhower, 

Nuclear War Fighting, and Korea: 1953-1968,” Presidential Studies Quarterly, 

Vol. 35, No. 1 (Mar 2005), 63-65.
170

 

89 For more on this concept, see Elbridge A. Colby, “The United States and 

Discriminate Nuclear Options in the Cold War,” chapter 3 in On Limited 

Nuclear Warfare in the 21st Century, Jeffrey A. Larsen and Kerry M. Kartchner, 

eds. (Palo Alto, CA: Stanford University Press, forthcoming).

90 Scott D. Sagan, “SIOP-62: The Nuclear War Plan Briefing to President 

Kennedy,” International Security, Vol. 12, No. 1 (Summer 1987), 38.

91 “Guidance to the NATO Military Authorities,” #25 in Annex II, NATO 

Defence Planning Committee/Decisions, Document DPC/D (67) 23. 

92 Horst Mendershausen, From NATO to Independence: Reflections on de 

Gaulle’s Secession (Santa Monica, CA: RAND Corporation, 1966), 6, and 

Robbin F. Laird, “The French Strategic Dilemma,” Center for Naval Analyses, 

Paper #407 (November 1984), 2.

93 France remained politically engaged with the alliance and since the mid-1990s 

has gradually reintegrated with NATO military bodies. Its nuclear forces, 

however, remain separate from the alliance, and it is not a part of the NATO 

Nuclear Planning Group. See the discussion on “Flexibility of NATO 

Membership” within NATO, “Member Countries,” n.d. 

94 The Soviet Union tested its first ICBM, the R-7, in 1957. 

95 Walter S. Poole, The History of the Joint Chiefs of Staff and National Policy, 

1965-1968, Vol. iv (Washington D.C.: Department of Defense), 318-319.

96 Thomas A. Schwartz, “NATO, Europe, and the Johnson Administration,” 

NATO Research Fellowship Program paper, 15.

97 Marc Trachtenberg, A Constructed Peace (Princeton, N.J.: Princeton 

University Press, 1999), 204-210. 

98 Freedman, The Evolution of Nuclear Strategy, 313. 

99 NATO, “The Harmel Report.” 

100 New York Times, “LBJ Urges a Buildup for NATO,” re-published in The 

Miami News, September 10, 1965, 8B, and Mary N. Hampton, The Wilsonian 

Impulse: U.S. Foreign Policy, the Alliance, and German Unification (Westport, 

CT: Praegar Publishers, 1996), 112.

101 J. Robert Oppenheimer, “Atomic Weapons and American Policy,” Foreign 

Affairs (July 1953), 529.

102 Missile Defense Agency, Nike Zeus: The U.S. Army’s First Antiballistic 

Missile (Missile Defense Agency: n.d.), 1-10. 

103 Lt Col Charles E. Costanzo, “Shades of Sentinel? National Missile Defense 

Then and Now,” Aerospace Power Journal (Fall 2001), and Sharon Watkins 

Lang, “Who Do You Think You Are?” U.S. Army Space and Missile Defense 

Command Historical Essay, n.d. 
171

 

104 David Yost, Soviet Ballistic Missile Defense and the Western Alliance

(Boston, MA: Harvard University Press, 1988), 5. 

105 Ambassador Steven Pifer notes that by “early 1970s [there were] over 7,300 

[U.S. nuclear warheads in Europe], of which some 2,800 were designated for 

allied use under programs of cooperation.” Steven Pifer NATO, Nuclear 

Weapons, and Arms Control, Brookings Arms Control Series, Paper 7 (July 

2011), 6.

106 “Paper Provided by the Interagency SALT Steering Committee,” 31-32, n.d. 

in Erin Mahan, ed., Foreign Relations of the United States, 1969-1976, Volume 

XXXII, SALT I: 1969-1972 (United States Government Printing Office: 

Washington D.C., 2010), and Sir Michael Quinlan, “The Silent Alliance: UKFRG Defence Relationships, 1968-69,” 189 in Manfred Gortemaker, Britain and 

Germany in the 20th Century (Oxford International Publishers: Oxford, 2006).

107 NATO, “Alliance Defence for the Seventies,” December 4, 1970. 

108 North Atlantic Council, Final Communique, Brussels, December 9-10, 1971.

109 In discussing the signing of the ABM Treaty and the SALT Interim 

Agreement, the North Atlantic Council stated their support for both accords, 

asserting they would “contribute to strategic stability, significantly strengthen 

international confidence, and reduce the danger of nuclear war.” North Atlantic 

Council, Final Communique, Bonn, May 30-31, 1972. The United Kingdom 

and France also quietly communicated to the United States their relief that the 

ABM Treaty a) made their own nuclear forces more credible, as the Soviet 

Union was now prevented from deploying a defense system that could negate 

their national offensive forces, and; b) obviated any need for their countries to 

pursue their own expensive national missile defense systems. “Minutes of a 

National Security Council Meeting,” Washington D.C, March 8, 1971, 417 and 

“Letter from the Personal Representative to the North Atlantic Treaty 

Organization (Ellsworth) to President Nixon,” Brussels, April 3, 1971, 438 in 

Mahan, ed., Foreign Relations of the United States.

110 North Atlantic Military Committee, “Final Decision on MC 14/3,” January 

16, 1968.

111 Paul Schulte, “Tactical Nuclear Weapons in NATO and Beyond: A Historical 

and Thematic Examination,” 41 in Tom Nichols, Douglas Stuart, and Jeffrey D. 

McClausland, eds. Tactical Nuclear Weapons in NATO (Carlisle PA: U.S. Army 

War College Strategic Studies Institute, 2012). 

112 Secretary of Defense James Schlesinger, Annual Defense Department Report 

for FY1975 (Washington: U.S. Government Printing Office, 1974), 38, 44. 

113 National Security Decision Memorandum 242 (NSDM 242), January 17, 

1974.

114 Hosking, Russia and the Russians, 517. 
172

 

115 Richard Burt, “The SS-20 and the Eurostrategic Balance,” The World Today, 

Vol. 33, No. 2 (February 1977), 45-46. 

116 State Department, “SCC Meeting on PRM-38,” Briefing Memo, August 23, 

1978.

117 State Department, “INF Treaty: Narrative,” n.d., 

http://www.state.gov/t/avc/trty/102360.htm , and NATO – Allied Command 

Operations, “1979-1989: ‘Dual Track’ Decade – New Weapons, New Talks,” 

n.d.

118 Benjamin B. Fischer, “A Cold War Conundrum: The 1983 Soviet War 

Scare,” CIA Center for the Study of Intelligence monograph, 1997.

119 President Ronald Reagan, “Address to the Nation on Defense and National 

Security,” address, Washington D.C., March 23, 1983. 

120 At the 1985 superpower summit in Reykjavik, for example, Reagan 

suggested to Soviet leader Mikhail Gorbachev that U.S. missile defense 

technology could be shared with the Soviet Union, ultimately permitting both 

sides to deploy effective defenses and, in turn, agree to deep reductions in their 

nuclear arsenals. Gorbachev apparently rejected the offer as unrealistic, noting 

that the United States refused to make even benign civilian technologies such as 

“oil drilling equipment, automatic machinery, even milk factories” available to 

the Soviet Union. Tom Simons, “Memorandum of Conversation,” U.S. 

delegation memorandum, Hofdi House, Reykjavik, October 11, 1986, 5, 14-15. 

121 Christopher Bertram, “Strategic Defense and the Western Alliance,” 

Daedalus, Vol. 114, No. 3 (Summer 1985), 281.

122 William Tuohy, “Former German Chancellor Assails ‘Star Wars’ and U.S. 

Deficit,” Los Angeles Times, September 11, 1986.

123 Susan J. Koch, The Presidential Nuclear Initiatives of 1991-1992, National 

Defense University Center for the Study of Weapons of Mass Destruction Case 

Study #5 (National Defense University: Washington D.C., 2012), 6. 

124 Koch, 11.

125 Lacking any formal verification mechanism, however, it is uncertain if these 

measures were fully carried out. See David Yost, “Russia and Arms Control for 

Non-strategic Nuclear Weapons,” in Larsen and Klingenberger, Controlling 

Non-Strategic Nuclear Weapons (United States Air Force Institute for National 

Security Studies, 2001), 133-137. 

126 President George H.W. Bush, “Address to the Nation on Reducing United 

States and Soviet Nuclear Weapons,” September 27, 2001.

127 Ibid.

128 Koch, 11.
173

 

129

 North Atlantic Council, “The Alliance’s New Strategic Concept,” November 

8, 1991, #36, 39.

130 While “missile defenses” are not further defined within the document, most 

alliance members probably viewed these defenses as either theater missile 

defense systems similar to the U.S. Patriot systems used during the 1991 Gulf

War or a “limited” national defense system capable of intercepting a small 

number of missiles (but not negating the Russian Federation’s nuclear 

deterrent). U.S. officials briefed the latter type of system to NATO allies in 

May 1991. North Atlantic Council, “The Alliance’s New Strategic Concept,” 

#49, and NATO Defense Planning Committee and Nuclear Planning Group, 

“Final Communique,” #14, May 29, 1991. 

131 DoD, Nuclear Posture Review, briefing, September 22, 1994, slide 35.

132 Congressional Commission on the Strategic Posture of the United States, 

America’s Strategic Posture (United States Institute of Peace: Washington D.C., 

2009), 8-9.

133 DoD, Nuclear Posture Review, briefing, September 22, 1994, slide 4.

134 Nuclear Posture Review, briefing, September 22, 1994, slide 2.

135 Testimony of Deputy Secretary of Defense John M. Deutch. Hearing before 

the Senate Armed Services Committee, 103rd Congress, September 22, 1994 (S. 

Hrg. 103-870), 16.

136 CNN, “Clinton Delivers Speech on National Missile Defense,” address 

transcript, September 1, 2000, Washington D.C., and Office of the President, 

“National Security Strategy for a New Century,”16 (hereafter NSS 1999). 

137 Late within his term, President Clinton elected not to deploy national missile 

defense, citing recent test failures and a desire to adjust the terms of the ABM 

Treaty, leaving a decision on deployment to a future administration. 

138NSS 1999, 35, and Richard P. Cronin, Japan-U.S. Cooperation on Ballistic 

Missile Defense, CRS Report, March 19, 2002, 1.

139 Camille Grand, “Missile Defense: The View from the Other Side of the 

Atlantic,” Arms Control Today (online edition), September 2000. See also

Australia Department of Foreign Affairs and Trade, “Australia-United States 

Ministerial Consultations 1999 Joint Communique,” November 3, 1999: 

“Australia encouraged the United States to pursue amendments [to NMD plans] 

consistent with the spirit and intent of the ABM Treaty in order to maintain an 

effective Treaty relevant to new strategic circumstances.”

140 NATO Defence Nuclear Planning Group, “Final Communique,” December 

15, 1994, #20.

141 Grand, “Missile Defense.” 
174

 

142 CNN, “Clinton Delivers Speech on National Missile Defense,” address 

transcript, September 1, 2000.

143 In 1993, for example, it suggested reducing these forces from 185,000 to 

100,000 troops. Eric Schmitt, “Clinton Seeking $14 Billion Cut by the 

Military,” New York Times, February 4, 1993. 

144 North Atlantic Council, “The Alliance’s Strategic Concept,” April 24, 1999, 

#41.

145 Ibid, #42 and 56.

146 Richard McMillan, Aegis TMD: Implications for Australia, Australian 

Defence College, Monograph Series, No. 1, 50.

147 Colonel Patrick M. O’Donogue, “Theater Missile Defense in Japan,” 

Strategic Studies Institute report, September 2000, 3-7. 

148 Office of the Press Secretary, The White House, “Remarks by the President 

to Students and Faculty at National Defense University,” Washington D.C., May 

1, 2001 cited by Keith B. Payne, “The Nuclear Posture Review: Setting the 

Record Straight,” The Washington Quarterly, Vol. 28, No. 3 (Summer 2005), 

135.

149 “The U.S. will no longer plan, size or sustain its forces as though Russia 

presented merely a smaller version of the threat posed by the former Soviet 

Union.” Donald Rumsfeld, Foreword, Nuclear Posture Review Report, January 

9, 2002. See also Department of Defense, “Findings of the Nuclear Posture 

Review,” briefing, January 9, 2002, slide 6, and Department of Defense, Office 

of the Assistant Secretary of Defense for Public Affairs, “Special Briefing on the 

Nuclear Posture Review,” briefing transcript, January 9, 2002. “[We seek] a 

new framework of relations that sets aside the sort of Cold War hostilities, in 

particular the idea of ending the relationship with Russia that is based on mutual 

assured destruction.”

150 Payne, “The Nuclear Posture Review: Setting the Record Straight,” 138.

151 Donald Rumsfeld, “Foreword,” Nuclear Posture Review Report, January 9, 

2002. 

152 Donald Rumsfeld, Annual Report to the President and Congress, Department 

of Defense report (2002), 88 and “Foreword,” Nuclear Posture Review Report.

153 Walter Pincus, “Bush Request to Fund Nuclear Study Revives Debate,” 

Washington Post, February 9, 2005, A9. 

154 Rumsfeld, “Foreword,” Nuclear Posture Review Report.

155 Ibid. 

156 Rumsfeld, Annual Report to the President and Congress, 84.
175

 

157 Ibid. 

158 Department of Defense, “Special Briefing on the Nuclear Posture Review,” 

January 9, 2002.

159 Department of Defense, “Findings of the Nuclear Posture Review,” briefing, 

January 9, 2002, slide 7.

160 Ibid.

161 Department of Defense, “Special Briefing on the Nuclear Posture Review,” 

January 9, 2002.

162 Ibid, slide 6. 

163 “Bush’s Missile Defense Stance Prompts Allies to Mull Options,” National 

Defense [online edition], July 2011. 

164 Stanley R. Sloan, “How and Why Did NATO Survive the Bush Doctrine?” 

NATO Defense College Research Report, 2008, 3-4. 

165 David Yost, “The US Nuclear Posture Review and the NATO Allies,” 

International Affairs, Vol. 80, No. 4, 726.

166 NATO, “Bucharest Summit Declaration,” April 3, 2008, #37; CNN, “Bush: 

Missile Shield No Threat to Russia,” April 1, 2008; and Wade Boese, “NATO 

Summit Results Falls Short of Bush Goals,” Arms Control Today [online 

edition], May 2008. 

167 Department of Defense, Office of the Undersecretary of Defense for 

Acquisition, Logistics, and Technology, “ABM Treaty: President Putin 

Statement December 13, 2001,” n.d.

168 NATO, “Comprehensive Political Guidance,” November 29, 2006, #5 and 7. 

169 Ibid, #16e. 

170 Stephen McFarland. “The Air Force in the Cold War, 1945-1960,” Airpower 

Journal [online edition] (Fall 1996). 

171 Elbridge Colby, “The United States and Discriminate Nuclear Options in the 

Cold War,” in On Limited Nuclear Warfare in the 21st Century, 88.

172 During the Cold War, for example, the Soviet Union deployed medium-range 

nuclear missiles capable of targeting the European members of NATO: “The 

aim was to take Western Europe hostage: since any threatened missile strike 

there would not directly affect the United States, the Soviet leaders hoped the 

American leaders would not respond effectively [to the threat], and a split would 

open up within NATO.” Geoffrey Hosking, Russia and the Russians: A History, 

2

nd ed. (Cambridge, MA: Harvard University Press, 2011), 517.

173 Denis Healey, The Time of My Life (London: Michael Joseph, 1989), 243. 

Found in Bruno Tertrais, “The Future of Extended Deterrence: A Brainstorming 
176

 

Paper,” in Perspectives on Extended Deterrence (Fondation pour la Recherche 

Strategique, Recherches et documents no. 3, 2010), 8. 

174 Amy L. Catalinac, “Why New Zealand Took Itself Out of ANZUS,” Foreign 

Policy Analysis Vol. 6 (2010), 317-319. 

175 David Alexander, “U.S. Lifts Ban on New Zealand Warships, New Zealand 

Keeps Nuclear-free Stance,” Reuters, September 21, 2012. 

176 New Zealand remains committed to its “nuclear free” policy, and by law 

continues to bar entry to any nuclear-powered ship and to any ship or aircraft 

carrying nuclear weapons. New Zealand Parliament, New Zealand Nuclear Free 

Zone, Disarmament and Arms Control Act of 1987, Public Act 86, June 8, 1987, 

Articles 9-11. 

177 NSS 2010. “The United States of America will continue to underwrite global 

security .... [But as] we do, we must recognize that no one nation – no matter 

how powerful – can meet global challenges alone.” See also the 2010 QDR 

“[The United States] cannot sustain a stable international system alone” (2010 

QDR, 63). 

178 Joseph Nye, “The U.S. can Reclaim ‘Smart Power,’” LA Times, January 21, 

2009. 

179 Assistant Secretary of State Esther Brimmer, “UNGA 67 and U.S. 

Multilateral Priorities,” address, Center for Strategic and International Studies, 

Washington D.C., September 18, 2012. “[A]round the globe, U.S. multilateral 

leadership similarly has helped assemble broad coalitions to address crises and 

avert or stem violent conflict.”

180 2010 NPT, iv. 

181 2010 BMDR, 7-8. 

182 2010 QDR, 17-45. 

183 As stated in the 2012 DSG: “we developed a defense strategy that transitions 

our Defense enterprise from an emphasis on today’s wars to preparing for future 

challenges, protects the broad range of U.S. national security interests, advances 

the Department’s efforts to rebalance and reform, and supports the national 

security imperative of deficit reduction through a lower level of defense 

spending.” (2012 DSG, 1). 

184 See, for example: 

 1) 2010 QDR: “The second theme to emerge from QDR analyses is the 

importance of ensuring that U.S. forces are flexible and adaptable so that they 

can confront the full range of challenges that could emerge from a complex and 

dynamic security environment.” (2010 QDR, 18);

 2) 2010 BMDR: “In the short term, the United States will address this 

mismatch between supply and demand with a comprehensive force management 
177

 

process that adjudicates competing requirements from the combatant commands. 

This approach underscores the value of developing capabilities that are flexible 

and adaptive and also relocatable, so that they can be surged into troubled 

regions in times of political-military crisis.” (2010 BMDR, 26). 

185White House Office of the Press Secretary, “Remarks by President Obama at 

the Brandenburg Gate, Berlin, Germany” 2013.

186White House Office of the Press Secretary, “Remarks by President Barack 

Obama, Hradcany Square, Prague, Czech Republic,” 2009. 

187 Ibid. 

188 2010 NPR, v-vi. 

189 2010 NPR, 30.

190 Ibid, 23.

191 In response to a question on New START’s force limits, Secretary of 

Defense Bill Gates, Secretary of State Hillary Clinton, and Chairman of the Joint 

Chiefs of Staff Admiral Mullen stated that the administration’s analysis of U.S. 

nuclear force requirements had found “the limits contained in the New START 

Treaty would be sufficient to support our deterrence requirements, including 

extended deterrence for our allies, in the current and projected international 

security environment.” Government Printing Office, “The New START Treaty 

(Treaty Doc. 111-5),” Hearings Before the Committee on Foreign Relations, 

United States Senate, 111th Congress (second session), April-May 2010, 78.

1922013 RENS: DoD, Report on Nuclear Employment Strategy of the United 

States Specified in Section 491 of 10 U.S.C, June 12, 2013, 3.

1932012 DSG: “Whenever possible, we will develop innovative, low-cost, and 

small-footprint approaches to achieve our security objectives, relying on 

[combined] exercises, rotational presence, and advisory capabilities” [emphasis 

in original]. (2012 DSG, 3).

194 2010 QDR, 13, 26.

195 Office of the President, 2010 National Space Policy [2010 NSP], 6 and DoD, 

2011 National Security Space Strategy [2011 NSSS], 9. 

196 Australian Government, Department of Defense, “Minister of Defence -

Interview with David Speers on SKY News, PM Agenda,” September 15, 2011.

197 2010 DSG, 3. 

198 2010 QDR, 8.

199 2006 DOJOC, 25.

200 2010 QDR, 14. The importance of tailoring extended deterrence and 

assurance strategies is also emphasized by documents such as the 2010 BMDR, 
178

 

which states that “regional approaches [to missile defenses] must be tailored to 

the unique deterrence and defense requirements of each region, which vary 

considerably in their geography, in the history and character of the threat, and in 

the military-to- military relationships on which to build cooperative missile 

defenses.” 2010 BMDR, 22.

201 House Armed Services Committee, “Statement of Dr. Brad Roberts, Deputy 

Assistant Secretary of Defense for Nuclear and Missile Defense Policy Before 

the House Armed Services Committee,” Congressional testimony, March 31, 

2011, Washington D.C.

202 2010 NSS, 22. “Military force, at times, may be necessary to defend our 

country and allies or to preserve broader peace and security .... [This requires] 

credibly underwriting U.S. defense commitments with tailored approaches to 

deterrence and ensuring the U.S. military continues to have the necessary 

capabilities across all domains – land, air, sea, space, and cyber.” 

203 2010 NSS, 23-24, 26; 2010 BMDR, 6-7; 2012 NSS 2,4,5.

204 2010 BMDR, 6-7.

205 2010 NPR, ix-xii, 19-30. 

206 2013 RENS, 3.

207 Ibid. 

208 2012 DSG, 4. 

209 U.S. Senate Committee on Armed Forces, Subcommittee on Strategic Forces, 

Joint Statement for the Record, The Honorable Madelyn Creedon, Assistant 

Secretary of State for Global Security Affairs and the Honorable Andrew 

Weber, Assistant Secretary of Defense for Nuclear, Chemical, and Biological 

Defense Programs on Fiscal Year 2013 National Defense Authorization Budget 

Request for Department of Defense Nuclear Forces Programs, Washington D.C., 

March 28, 2012. 

210 2010 NPR, 28. “U.S. nuclear weapons will play a role in the deterrence of 

regional states so long as those states have nuclear weapons, but the decisions 

taken in the NPR, BMDR, and QDR reflect the U.S. desire to increase reliance 

on non-nuclear means to accomplish our objectives of deterring such states and 

reassuring our allies and partners.”

211 See, for example, the 2010 QDR’s discussion of American conventional 

forces in the ROK: “The United States will develop a more adaptive and flexible 

U.S. and combined force posture on the Korean Peninsula to strengthen the 

alliance’s deterrent and defense capabilities and long-term capacity for regional 

and global defense cooperation.” 2010 QDR, 66. 

212 2010 QDR, 26. “Security cooperation activities include bilateral and 

multilateral training and exercises ... and efforts to assist foreign security forces 
179

 

in building competency and capacity. In today’s complex and interdependent 

security environment, [training and other dimensions] of the U.S. defense 

strategy have never been more important. U.S. forces, therefore, will continue to 

treat the building of partners’ security capacity as an increasingly important 

mission.” 

213 As noted by Admiral Samuel Locklear in April 2013 Congressional 

testimony on the U.S. defense posture in the Asia-Pacific: “Moving forward, to 

better deter and defeat aggression, USPACOM is taking steps to improve intheater critical munitions stockpiles. In the past year, U.S. Army Pacific and 

U.S. Forces Korea have seen tangible benefits from the rebalance, improving 

their ability to meet future requirements through enhanced prepositioned 

stocks.” U.S. Senate Armed Services Committee, Statement of Admiral Samuel 

J. Locklear, U.S. Navy Commander, U.S. Pacific Command Before the Senate 

Armed Services Committee on U.S. Pacific Command Posture, Washington 

D.C., April 9, 2013.

214 2010 NPR, xi.

215 2010 NPR, 24.

216 NATO extended deterrence strategies also include allied Tornado aircraft. 

217 The Nuclear Matters Handbook: Expanded Edition, available at 

http://www.acq.osd.mil/ncbdp/nm/nm_book_5_11/. “The B61 bomb has had 11 

variations over time ... Five of these Mods [modifications] are still in the 

current stockpile: B61-3, B61-4, b61-7, B61-10, B61-11.” Nuclear Matters, 30. 

The B61-3/4 are carried by DCA; the B61-7/11 are carried by bombers. Nuclear 

Matters, 45. 

2182010 NPR, 24. “Nuclear-capable bombers are important to extended 

deterrence of potential attacks on U.S. allies and partners. Unlike ICBMs and 

SLBMs, heavy bombers can be visibly forward deployed, thereby signaling U.S. 

resolve and commitment in crisis.” 

219 Rebecca Grant, “Nukes for NATO,” Air Force Magazine, Vol. 93, No. 7 

(July 2010). 

220 2010 BMDR, 6-7. 

221 2010 BMDR, 12. 

222 2010 BMDR, vi and 2010 QDR, 103.

223 2010 BMDR, 23.

224 See “Strengthening Regional Deterrence and Reassuring U.S. Allies and 

Partners,” 2010 NPR, 31-35. 

225 Ibid, 34.

226 Ibid, xiii, xiv, 28.
180

 

227 Ibid, 48.

228 2010 QDR, 63.

229 2013 RENS, 8-9.

230 2010 NPR, xii. 

231 NATO, “Deterrence and Defense Posture Review,” NATO Press Release No. 

063, May 20, 2012 [hereafter 2012 DDPR].

232 2010 BMDR, 26. 

233 Ibid, 12.

234 Ibid., 25

235 The USS Abraham Lincoln aircraft carrier, for example, has played an 

important role in the past in deterring Iranian threats to close the Straits of 

Hormuz or otherwise harass shipping in the Persian Gulf. Budget cuts in early 

2013 indefinitely suspended a scheduled refuel/refit required for the carrier to 

resume future operations. A continuing resolution in Congress in late March 

provided the necessary funding, but the carrier’s time in limbo provides an 

illustration of how cuts in funding (particularly if amounts and/or timelines 

associated with cuts are not anticipated in advance) can sideline key U.S. 

deterrence assets. Joshua Stewart, “After Delay, USS Lincoln Arrives for 

Midlife Refuel,” Navy Times, March 28, 2013 and Jim Miklaszewski, “USS 

Lincoln Sails Through Straits of Hormuz,” NBC News, January 23, 2012. 

236 In mid-2007 Estonia, a member of NATO, experienced a series of persistent 

denial of service attacks across a range of public and private cyber networks. 

The volume and scope of the attacks indicated a level of coordination and 

strategic planning that led some experts – and most Estonians – to suspect the 

attacks represented a covert, state-sponsored cyber campaign. The United States 

and other NATO allies established a Cooperative Cyber Defence Centre of 

Excellence for the alliance in Estonia’s capital, Talinn, in May 2008, one year 

after the attacks. Jaak Aavikso, “Cyber Defence: The Unnoticed Third World 

War,” address, 24th International Workshop on Global Security, Paris, June 16, 

2007.

237 2010 QDR, 18 and 2010 BMDR, 26, 47.

238“Statement of General Keith B. Alexander, Commander, United States Cyber 

Command, Before the Senate Committee on Armed Services,” U.S. Senate, 

Washington D.C., March 12, 2013, 3, 5. 

239 Victor Cha, “North Korea Threatens to Strike the United States,” CSIS 

Critical Questions, March 29, 2013.

240 DoD, Joint Operational Access Concept [hereafter JOAC], January 17, 2012, 

i. 
181

 

241 Vincent Manzo, “Deterrence in Cross-Domain Operations: Where Do Space 

and Cyberspace Fit?” Joint Force Quarterly, Vol. 66 (July 2012) [online 

edition].

242 Ibid, 36. 

243 2010 QDR, 8. 

244 2012 DSG, 3 and JOAC, 1-2. 

245 In this hypothetical situation, the United States would likely cover the ally 

beneath a regional nuclear umbrella, using assets outside of the ally’s territory 

(such as SSBNs on patrol). Some allies, however, might insist that U.S. nuclear 

forces stationed on its own territory represent the only credible deterrent to a 

nuclear-armed adversary. 

246 As noted by Director of National Intelligence James R. Clapper in April 2013 

testimony before Congress: “We lack uniform agreement on assessing many 

things in North Korea.” Office of the Director of National Intelligence, Public 

Affairs Office, “Remarks as Delivered by James R. Clapper, Director of 

National Intelligence, Worldwide Threat Assessment to the Senate Armed 

Services Committee,” April 18, 2013. 

247 Secretary of Defense Robert Gates, “The Security and Defense Agenda 

(Future of NATO),” address, Brussels, Belgium, June 10, 2011. 

248 Malcolm Chalmers, “The Squeeze Continues,” RUSI Analysis, March 25, 

2013, and Nick Hopkins, “Defence Cuts: Thousands of Soldiers Could Face 

Compulsory Redundancy,” The Guardian, July 5, 2012.

249 F. Stephen Larrabee, “NATO Forces Approach Financial Day of Reckoning,” 

RAND Review (Winter 2012-2013) [online edition]. 

250 Merle David Kellerhals, Jr. “State’s Tauscher Discusses Progress on Missile 

Defense,” State Department Bureau of International Information Programs, 

March 27, 2012. 

251 2013 RNES, 3. 

252 “Putin Pushes Nuclear, Space Defense Reform,”RT.com, July 26, 2012. 

253 Two days after the 2012 U.S. presidential election, Russian Deputy Foreign 

Minister Sergey A. Ryabkov publicly stated that nuclear deterrence remained 

central to U.S.-Russian relations: “[Nuclear] deterrence is based on the state 

leadership understanding of the impossibility of the achieving of their objectives 

by military means, even in the event of a first nuclear strike, because the other 

party could maintain the opportunity for crushing response under all conditions 

of the war start. Despite the fact that Russian-American relations have been 

improved in recent years, and the nuclear potentials of the parties have been 

significantly reduced by bilateral agreements on START, strategic stability in 

relations between the two countries continues to be based on mutual deterrence.” 
182

 

Deputy Minister of Foreign Affairs of Russia Sergey A. Ryabkov, “Nuclear 

Disarmament and International Security in the 21st Century,” address, Russian 

Council on International Affairs conference, Moscow, November 8, 2012. See 

also Government of the Russian Federation, “The Military Doctrine of the 

Russian Federation,” February 5, 2010, 8a [English translation provided by 

Carnegie Endowment for International Peace, Washington, D.C.].

254 Major General Yao Yunzhu, “China will not Change its Nuclear Policy,” 

China-U.S. Focus, April 22, 2013. 

255 2010 BMDR, 26. 

256 Missile Defense Agency, “Terminal High Altitude Area Defense,” MDA 

Fact Sheet, April 2013. 

257 “Evidence in Hacker Attack Points to North Korea,” Chosun Ilbo [English 

edition], April 11, 2013, and Ben Farmer, “World’s Biggest Anti-Mine Naval 

Exercise After Iranian Threats to Close Gulf,” The Telegraph, May 13, 2012. 

2582010 BMDR, vi. “The United States seeks to create an environment in which 

the development, acquisition, deployment, and use of ballistic missiles by 

regional adversaries can be deterred, principally by eliminating their confidence 

in the effectiveness of such attacks.”

259 Office of the Director of National Intelligence, Public Affairs Office, 

“Remarks as Delivered by James R. Clapper,” April 18, 2013. 

260 “North Korean Army says it has ‘Ratified’ Nuclear Strike Against the U.S.,” 

Reuters, April 3, 2013. 

261 Cheon Seongwhun, “Changing Dynamics of U.S. Extended Deterrence on 

the Korean Peninsula,” NAPSNet Special Report, November 10, 2010.

262 Ken Jimbo, “Extended Deterrence in the Japan-U.S. Alliance,” NAPSNet 

Special Report, May 8, 2012.

263 Robert Marquand, “Amid Crisis, Influential South Korean Politician Wants 

to Deploy US Nukes,” Christian Science Monitor, April 9, 2013. 

264 Danielle Demetriou, “Japan ‘Should Develop Nuclear Weapons,’ to Counter 

North Korea Threat,” The Telegraph, April 20, 2009, and Yuri Kageyama, 

“Japan Pro-Bomb Voices Grow Louder Amid Nuke Debate,” Associated Press, 

July 31, 2012.

265 Kim Jiyoon, Karl Friedhoff, and Kang Chungku, “The Fallout: South Korean 

Public Opinion Following North Korea’s Third Nuclear Test,” Asan Institute for 

Policy Studies, Issue Brief No. 46, February 25, 2013, 8-10. 

266 “54 Pct of Turks Support Nukes if Iran has them,” Turkish Weekly, March 29, 

2012. 
183

 

267 Henri J. Barkey “Turkey’s Perspective on Nuclear Weapons and 

Disarmament,” 67-68 in Barry Blechman, ed. Unblocking the Road to Zero: 

Perspectives of Advanced Nuclear Nations (Brazil, Japan and Turkey), Nuclear 

Security Series Vol. VI (Stimson Center, Washington D.C., 2009).

268 Andrea Shalal-Esa, “Insight: Expensive F-35 Fighter at Risk of Budget 

‘Death Spiral,’” Reuters, March 15, 2013. 

269 Bill Carey, “U.S. Air Force is ‘Committed’ to Long-Range Strike Bomber,” 

AIN Online, January 18, 2013, and Kris Osborne, “Next Generation Bomber 

Survives Budget Tightening,” DefenseTech, April 22, 2013.

270 Government Accounting Office, DoD and NNSA Need to Better Manage 

Scope of Future Refurbishments and Risks to Maintaining U.S. Commitments to 

NATO, GAO 11-387, May 2011, 27-34. 

271 Jen DiMascio, “Nuclear Bomb’s Cost Draws Increased Congressional 

Scrutiny,” Aviation Week and Space Technology, August 6, 2012. 

272 2010 NPR, x-xi. 

273 2010 QDR, 66.

274 2010 BMDR 6-7.

275 Ibid. 

276 2010 NPR, xiii.

277 Secretary of Defense Leon Panetta, for example, has stated: “I know that 

many in the region and across the world are closely watching the United StatesChina relationship. Some view the increased emphasis by the United States on 

the Asia-Pacific region as some kind of challenge to China. I reject that view 

entirely. Our effort to renew and intensify our involvement in Asia is fully 

compatible -- fully compatible -- with the development and growth of 

China. Indeed, increased U.S. involvement in this region will benefit China as it 

advances our shared security and prosperity for the future” (Secretary of 

Defense Leon E. Panetta, address, Shangri-La Conference, Singapore, June 2, 

2012). While Asian-Pacific governments have generally demurred regarding 

whether China is the focus of the U.S. “rebalance,” regional commentators have 

concluded the policy shift reflects a U.S. desire to “contain” or “balance against” 

Beijing. D. Suba Chandran, “The Great Game,” Rising Kashmir, September 28, 

2012; David Brewster, “‘Asian Pivot’ is Really an ‘Asian Rebalance,’” Lowy 

Interpreter, June 22, 2012, and Lt Gen (ret.) Noboru Yamiguchi, “America’s 

‘Return’ to Asia Requires Japan’s Strategic Response,” AJISS-Commentary, 25 

Apr 2012.

278 2010 BMDR, 4, 12-13.
184

 

279 Li Bin, “What China’s Missile Intercept Test Means,” Carnegie Article, 

February 4, 2013, and “U.S. Missile Defense in East Asia,” Carnegie 

Proliferation Analysis, September 6, 2012. 

280 Secretary of Defense Leon E. Panetta, address, Shangri-La Conference, 

Singapore, June 2, 2012, and Robert M. Scher and David F. Helvey, “U.S. Force 

Posture in the U.S. Pacific Command Area of Responsibility,” Joint Statement 

to the House Armed Services Committee, August 1, 2012.

281 Radio Australia, “Singapore Agrees to Host Four New U.S. Warships,” June 

3, 2012, Office of the Prime Minister of Australia, “United States Marine Corps 

Personnel Begin First Rotational Deployment to Northern Australia,” press 

release, April 3, 2012, and “Reply by Minister of Defense Dr. Ng Eng Hen to 

Parliamentary Question on the U.S. Pivot Towards Asia,” transcript, Straits 

Times (Singapore).

282 In an October 2012 press conference in Manila, the captain of the carrier USS

George Washington told reporters “[o]ne of the reasons we deploy throughout 

the region is so we can carry forth the banner of freedom of navigation. It is very 

important to us given the trade that travels throughout the region on the sea.” 

Agence France Presse, “US Navy to Guard ‘Freedom of Navigation’ in Asia,” 

October 26, 2012. 

283 Secretary of Defense Leon E. Panetta, address, Shangri-La Conference, 

Singapore, June 2, 2012.

284 For an alternate view presented by a Chinese non-government expert on 

maritime law, see Zhang Haiwen, “Is it Safeguarding the Freedom of Navigation 

or Maritime Hegemony of the United States?” Chinese Journal of International 

Law, Vol. 9, no 1 (2010), 31-47. 

285 Manuel Mogato, “South China Sea Tension Mounts Near Filipino 

Shipwreck,” Reuters, May 29, 2013.

286 Erik Holmes, “More Russian Bombers Flying Off Alaskan Coast,” Air Force 

Times, April 6, 2008, Marc V. Schanz, “Strategic Alaska,” Air Force 

Magazine.com, November 2008, and “Russian Bombers Approach Alaska,” 

Global Security Newswire, February 6, 2009.

287 Japan Ministry of Foreign Affairs, “Japan’s Northern Territories: For a 

Relationship of Genuine Trust,” n.d., and “Russia to send Navy Vessels to 

Disputed Pacific Islands,” Reuters, August 14, 2012. 

288 2013 RNES, 3. “Consistent with the objective of maintaining an effective 

deterrent posture, the United States seeks to improve strategic stability by 

demonstrating it is not our intent to negate Russia’s strategic nuclear deterrent, 

or to destabilize the strategic military relationship with Russia.” 

289 2012 DSG, 2.
185

 

290 Governments of the United States of America and Japan, Japan-U.S. Security 

Treaty: Treaty of Mutual Cooperation and Security Between Japan and the 

United States of America, January 19, 1960.

291 “China Raises Stakes Over Disputed Island,” Financial Times, October 28, 

2012. 

292 For example, as stated in Japan’s Ministry of Defense white paper “Defense 

of Japan 2012,” “The military presence of the U.S. forces in Japan not only 

contributes to the defense of Japan, but also functions as deterrence against and 

response to contingencies in the Asia-Pacific region, and serves as a core 

element of the Japan-U.S. Security Arrangements.” Japan Ministry of Defense, 

“Defense of Japan 2012,” 220. 

293 Karen Parrish, “Japan, U.S. Begin Coordination on Second Radar 

Installation,” American Forces Press Service, September 17, 2012.

294 2010 NPR, 32. 

295 State Department, “Joint Statement of the U.S.-Japan Security Consultative 

Committee,” June 21, 2011. 

296 Embassy of Korea-United States, “The ROK-US Mutual Defense Treaty,” 

n.d. 

297 “Arms Buildup of U.S. Forces in South Korea Blasted,” KCNA (Japan), 

March 31, 2013. 

298 Brigadier General Kim Seung Taek (ROK), “Rethinking Extended 

Deterrence,” CSIS Office of the Korea Chair report, July 2, 2010. 

299 In addition, the ROK’s most serious maritime territory dispute is with Japan, 

not China. Voice of America News, “Japan Protests South Korean Media Tour 

to Disputed Isle,” October 5, 2012. 

300 The ROK’s current missile defenses rely on German-built PAC-2 

interceptors. Song Sang-Ho, “Korean Plan Sparks Speculation about U.S. 

Missile Defense,” The Korea Herald, November 1, 2012.

301 Republic of Korea Ministry of Defense, Defense White Paper 2010, 34, 79.

302 “New Missile Guideline Big Step Forward to Deterring NK: Analysts,” The 

Korea Times, October 7, 2012, Choe Sang-hun “US Agrees to let South Korea 

Extend the Range of Ballistic Missiles,” New York Times, October 7, 2012, and 

Scott A. Snyder, “South Korea’s New Missile Guidelines and North Korea’s 

Response,” Council on Foreign Relations, October 9, 2012.

303 Ambassador Sung Kim, address, Asia Society, February 14, 2012.

304 Governments of Australia, New Zealand, and the United States of America, 

Security Treaty Between Australia, New Zealand, and the United States of 

America, September 1, 1951, Article IV.
186

 

305 Reuters, “U.S., Australia to add Cyber Realm to Security Treaty,” September 

14, 2012.

306 Government of Australia, Australia in the Asian Century, October 2012, 3. 

307 Office of the Prime Minister of Australia, “United States Marine Corps 

Personnel Begin First Rotational Deployment to Northern Australia,” press 

release, April 3, 2012.

308 Australian Department of Defense, “Defending Australia in the Asian Pacific 

Century: Force 2030,” 2009, 50. 

309 Staff Sgt Brian Stives, “Year of the B-52: Global Strike Command Delivers 

Deterrence Through Continuous Bomber Presence,” Air Force Global Strike 

Command Public Affairs press release, March 2, 2012.

310 2012 DSG, 4.

311 James A. Russell, “Extended Deterrence, Security Guarantees, and Nuclear 

Weapons: US Strategic and Policy Conundrums in the Gulf,” in Perspectives on 

Extended Deterrence, (Paris: Fondation pour la Recherche Strategique, 2010), 

68.

312 2010 BMDR, 6-7.

313 Secretary of State Hillary Clinton, address, American Jewish Committee 

Annual Gala Dinner, Washington D.C., April 29, 2010.

314 2010 BMDR, 6. 

315 Cheryl Pellerin, “Panetta: DoD Works with Jordan, Turkey on Syria 

Repercussions,” American Forces Press Service, October 10, 2012.

316 Mark Landler and David E. Sanger, “Clinton Speaks of Shielding Middle 

East from Iran,” New York Times, July 22, 2009. 

317 Nicole Gauoettte, “Clinton says US will use all Power to Stop Iran,” 

Bloomberg News, July 12, 2012. Secretary of State Clinton stated in July 2012 

that the United States “will use all elements of American power to prevent Iran 

from obtaining a nuclear weapon.”

318 Lewis Dunn, “Strategic Reassurance if Iran ‘Goes Nuclear’: A Framework 

and Some Propositions,” Strategic Insights, Vol. 8, No. 5 (December 2009). 

319 2012 DSG, 2. 

320 2010 QDR, 67.

321 President Barack Obama, address, AIPAC Policy Conference, Washington 

D.C., March 4, 2012, and 2012 DSG, 2.

322 The exercise, titled Austere Challenge 2012, simulated rocket and chem-bio 

munitions attacks carried out by unnamed adversaries against a joint U.S.-Israeli 
187

 

force. Associated Press, “U.S. Israel Carry Out Largest Joint Military Exercise 

as Violence Flares on Gaza Border,” Washington Post, October 24, 2012. 

323 BMDR 2010, 25, and Jim Garamone, “Iron Dome System Demonstrates 

U.S.-Israeli Partnership,” American Forces Press Service, August 1, 2012. 

324 2010 QDR, 61, and 2012 DSG, 2. 

325 Donna Miles and Karen Parris, “F-15 Sale to Saudi Arabia Part of Broader 

Effort,” American Forces Press Service, December 31, 2011.

326 2010 BMDR, 34

327 2010 BMDR, 34, and Jim Garamone, “U.S., Bahrain Discuss Regional 

Security Issues,” American Forces Press Service, December 18, 2010.

328 2010 QDR, 61. As noted by the 2012 DSG “the Arab Awakening presents 

both strategic opportunities and challenges. Regime changes, as well as tensions 

within and among states under pressure to reform, introduce uncertainty for the 

future,” (2012 DSG, 2). 

329 Rebecca A. Hopkins, Lebanon and the Uprising in Syria: Issues for 

Congress, CRS Report, February 2, 2012, 13-15.

330 2010 BMDR, 26. “[r]egional demand for U.S. BMD assets is likely to exceed 

supply for some years to come.” 

331 Michael R. Gordon, “In U.S. Exit From Iraq, Failed Efforts and Challenges,” 

New York Times, September 22, 2012.

332 2010 QDR, 58. 

333 2012 DSG, 2-3.

334 2010 QDR, 65.

335 In the 1970s the United States maintained some 300,000 troops with their 

combat equipment, and 7,300 tactical nuclear warheads for use on 11 different 

types of delivery systems, in Central Europe. Current U.S. plans are for the U.S. 

military to have 30,000 or fewer troops in Europe in 2015. “US to reduce troops 

in Europe to 30,000,” available at http://www.neurope.eu/article/us-armyeurope-announced-new-head.

336 NATO, Lisbon Summit Declaration, November 20, 2010, 36. Within the 

2010 Lisbon Declaration, NATO committed for the first time to defending “all 

NATO European” populations against adversary missile attack. 

337 2012 DDPR, #8, 20. “Nuclear weapons are a core component of NATO’s 

overall capabilities for deterrence and defence alongside conventional and 

missile defence forces” and “NATO missile defence capability, along with 

effective nuclear and conventional forces, will signal our determination to deter 
188

 

and defend against any threat from outside the Euro-Atlantic area to the safety 

and security of our populations.” 

338 2010 NPR.

339 NATO, Deterrence and Defense Posture Review, NATO press release No. 

63, May 20, 2012.

340 2010 NPR, xii.

341 Ibid.

342 2010 NPR, 34-35.

343 2012 DDPR.

344 2010 BMDR, 30.

345 2010 BMDR, 29. 

346 Hans Kristensen and Robert S. Norris, Nuclear Notebook series, Bulletin of 

the Atomic Scientists, updated regularly, available at 

http://bos.sagepub.com/content/68/5/96.abstract. In particular, see 

“Nonstrategic Nuclear Weapons 2012,” September/October 2012, “U.S. Nuclear 

Forces 2012,” May/June 2012, “British Nuclear Forces 2011,” 

September/October 2011, “U.S. Tactical Nuclear Weapons in Europe, 2011,” 

January/February 2011, and “Global Nuclear Weapons Inventories, 1945-2010,” 

July 2012.

347 Ibid. 

348 “54 Pct of Turks Support Nukes if Iran Has Them,” Journal of Turkish 

Weekly, 29 March, 2012.

349 Deputy Assistant Secretary of State Bureau of Arms Control Verification and 

Compliance Frank Rose, Remarks, Polish National Defense University, 

Warsaw, Poland, April 18, 2013. 

350 U.S. State Department, Bureau of Arms Control, Verification, and 

Compliance, “United States European Phased Adaptive Approach (EPAA) and 

NATO Missile Defense.” 

351 Chantal de Jonge Oudraat and Michael E. Brown, “Mostly Sunny, Partly 

Cloudy,” SIPRI Analysis No. 8 (2012).

352 James Acton, “Extended Deterrence and Communicating Resolve,” Strategic 

Insights, Volume VIII, Issue 5, December 2009.

353 Elaine Bunn, “The Future of US Extended Deterrence,” 46.

354 Clark Murdock et al. Exploring the Nuclear Posture Implications of 

Extended Deterrence and Assurance, 1.
189

 

355 Keith Payne, “How Much is Enough? A Goal-Driven Approach to Defining 

Key Principles,” National Institute for Public Policy, 2009, 5.

356 Keith Payne, “On Nuclear Deterrence and Assurance,” 44. 

357 Joseph Pilat, “Nonproliferation, Arms Control and Disarmament, and 

Extended Deterrence in the New Security Environment,” Strategic Insights,

September 2009.

358 Ibid.

359 James Russell, “Extended Deterrence, Security Guarantees, and Nuclear 

Weapons,” in Perspectives on Extended Deterrence, (Paris: Fondation pour la 

Recherché Strategique, Recherches et documents no.3), March 2010, 74.

360 Ibid,74.

361 Mark Schneider, “The Future of the US Nuclear Deterrent,” Comparative 

Strategy, Vol. 27, Issue 4, 2008, 346.

362 James Schoff, “Does the Nonproliferation Tail Wag the Deterrence Dog?” 

PacNet 9, CSIS, 5 February 2009.

363 Bruno Tertrais, “Security Guarantees and Extended Deterrence in the Gulf 

Region: A European Perspective,” Strategic Insights, Vol. VIII, Issue 5, 

December 2009, 29.

364 Ibid, 31.

365 Tertrais, Perspectives on Extended Deterrence, 8.

366 David Trachtenberg, “U.S. Extended Deterrence: how Much Strategic Force 

is Too Little?” Strategic Studies Quarterly, Summer, 2012, 62.

367 David Yost, “Assurance and U.S. Extended Deterrence in NATO,” 759-764.
190

 
191

 

INSS OCCASIONAL PAPERS

 1. Explaining Weapon s Proliferation: Going Beyond the Security Dilemma. 

Gregory J. Rattray, July 1994.

 2. The Ukranian Military: Instrument for Defense or Domestic Challenge? Oleg 

Strekal, November 1994.

 3. North Korea’s Nuclear Program: The Clinton Administration’s Response. 

William E. Berry, Jr., March 1995

 4. Environmental Assistance as National Security Policy: Helping the Former Soviet 

Union Find Solutions to its Environmental Problems. Robert L. Dunaway, 

November 1995

 5. Economic Power in the Sino-U.S. Relationship. Kevin F. Donovan, December 

1995

 6. Nuclear Proliferation: Diminishing Threat? William H. Kincade, December 1995

 7. Nuclear Proliferation: The Diplomatic Role of Non-Weaponized Programs. 

Rosalind R. Reynolds, January 1996

 8. Five Minutes Past Midnight: The Clear and Present Danger of Nuclear Weapons 

Grade Fissile Materials. Guy B. Roberts, February 1996

 9. The International Legal Implications of Information Warfare. Richard W. 

Aldrich, April 1996

10. Weapons Proliferation and Organized Crime: The Russian Military and Security 

Force Dimension. Graham H. Turbiville, Jr., June 1996

11. Melancholy Reunion: A Report from the Future on the Collapse of Civil-Military 

Relations in the United States. Charles J. Dunlap, Jr., October 1996

12. Russia’s Crumbling Tactical Nuclear Weapons Complex: An Opportunity for 

Arms Control. Stephen P. Lambert and David A. Miller, April 1997

13. Political-Military Affairs Officers and the Air Force: Continued Turbulence in a 

Vital Career Specialty. James E. Kinzer and Marybeth Peterson Ulrich, April 1997

14. Environmental Federalism and U.S. Military Installations: A Framework for 

Compliance. James M. Smith, June 1997.

15. Nonlethal Weapons: Terms and References. Robert J. Bunker, July 1997.

16. Threat Perceptions in the Philippines, Malaysia, and Singapore. William E. 

Berry, Jr., September 1997.

17. NATO Counterproliferation Policy: A Case Study In Alliance Politics. Jeffrey A. 

Larsen, November 1997.

18. Uncharted Paths, Uncertain Vision: U.S. Military Involvements in Sub-Saharan 

Africa in the Wake of the Cold War. Dan Henk, March 1998.

19. USAF Culture and Cohesion: Building an Air and Space Force for the 21st Century. 

James M. Smith, June 1998.

20. A Post-Cold War Nuclear Strategy Model. Gwedolyn Hall, John T. Cappello, and 

Stephen P. Lambert, July 1998.
192

 

21. Counterforce: Locating and Destroying Weapons of Mass Destruction. Robert W. 

Chandler, September 1998.

22. Environmental Security in the Czech Republic: Status and Concerns in the PostCommunist Era, Paul J. Valley, October 1998.

23. NATO: Potential Sources of Tension, Joseph R. Wood, February 1999.

24. Juggling the Bear: Assessing NATO Enlargement in Light of Europe's Past and 

Asia's Future, David S. Fadok, March 1999.

25. The Next Peace Operation: U.S. Air Force Issues and Perspectives, William C. 

Thomas and Jeremy D. Cukierman, May 1999.

26. Interpreting Shadows: Arms Control and Defense Planning in a Rapidly Changing 

Multi-Polar World, David R. King, June 1999.

27. Out of (South) Africa: Pretoria’s Nuclear Weapons Experience, Roy E. Horton, III, 

August 1999.

28. The Chinese People’s Liberation Army: “Short Arms and Slow Legs,” Russell D. 

Howard, September 1999.

29. Overcoming Uncertainty: U.S. China Strategic Relations in the 21st Century, Walter 

N. Anderson, October 1999.

30. The Viability of U.S. Anti-Satellite (ASAT) Policy: Moving Toward Space Control, 

Joan Johnson-Freese, January 2000.

31. Indo-Russian Military and Nuclear Cooperation: Implications for U.S. Security 

Concerns, Jerome M. Conley, February 2000.

32. Cyberterrorism and Computer Crimes: Issues Surrounding the Establishment of an 

International Legal Regime, Richard W. Aldrich, April 2000.

33. Sharing the Knowledge: Government-Private Sector Partnerships to Enhance 

Information Security, Steven M. Rinaldi, May 2000.

34. Prospects for a Conventional Arms Reduction Treaty and Confidence-Building 

Measures in Northeast Asia, Bonnie D. Jenkins, August 2000.

35. Water: The Hydraulic Parameter of Conflict in the Middle East and North Africa, 

Stephen D. Kiser, September 2000.

36. This Arms Control Dog Won’t Hunt: The Proposed Fissile Material Cut-Off Treaty 

at the Conference on Disarmament, Guy B. Roberts, January 2001.

37. The Rollback of South Africa’s Biological Warfare Program, Stephen Burgess and 

Helen Purkitt, February 2001.

38. Constraints, Restraints, and the Role of Aerospace Power in the 21st Century, Jeffrey 

K. Beene, April 2001.

39. Aerospace Power in Urban Warfare: Beware the Hornet’s Nest, Peter C. Hunt, May 

2001.

40. US Policy Towards Succession in the Balkans and Effectiveness of De Facto 

Partition, Evelyn N. Farkas; and Improving US-Russian Relations Through 

Peacekeeping Operations, Beth L. Makros and Jeremy C. Saunders, June 2001.
193

 

41. The Common European Security and Defense Policy (ESDP), Edward G. Gunning, 

Jr., July 2001.

42. United States Military Space: Into the Twenty-First Century, Peter L. Hays, 2002 

(published jointly with Air University Press).

43. Lords of the Silk Route: Violent Non-State Actors in Central Asia, Troy S. Thomas 

and Stephen D. Kiser, May 2002.

44. “All Our Tomorrows”: A Long-Range Forecast of Global Trends Affecting Arms 

Control Technology, James M. Smith and Jeffrey A. Larsen, June 2002.

45. “Squaring the Circle”: Cooperative Security and Military Operation, Jeffrey D. 

McCausland, July 2002.

46. Tactical Nuclear Weapons: Debunking the Mythology, John T. Cappello, Gwendolyn 

M. Hall, and Stephen P. Lambert, August 2002.

47. Northeast Asia Regional Security and the United States Military: Context, Presence, 

and Roles, Susan F. Bryant, Russell D. Howard, Jay M. Parker, and Albert S. Willner, 

November 2002.

48. View from the East: Arab Perceptions of United States Presence and Policy, Brent J. 

Talbot and Michael B. Meyer, February 2003.

49. Arms Control without Arms Control: The Failure of the Biological Weapons 

Convention Protocol and a New Paradigm for Fighting the Threat of Biological 

Weapons, Guy B. Roberts, March 2003.

50. Effects, Targets, and Tools: A Primer for US Strategy and an Application

Examining the Security Dynamics of Northeast Asia, Thomas A. Drohan, May 2003.

51. Egypt as a Failing State: Implications for US National Security, Ruth M. Beitler and 

Cindy R. Jebb, June 2003.

52. Violent Systems: Defeating Terrorists, Insurgents, and Other Non-State Adversaries, 

Troy S. Thomas and William D. Casebeer, March 2004.

53. The Worried Well: Strategies for Installation Commanders, Fran Pilch, April 2004.

54. India’s Emerging Security Strategy, Missile Defense, and Arms Control, Stephen F. 

Burgess, June 2004.

55. Perspectives on Arms Control, Michael O. Wheeler, James M. Smith, and Glen M. 

Segell, July 2004.

56. Carrot, Stick, or Sledgehammer: US Policy Options for North Korean Nuclear 

Weapons, Daniel J. Orcutt, August 2004.

57. Armed Groups: A Tier-One Security Priority, Richard H. Shultz, Douglas Farah, and 

Itamara V. Lochard, September 2004.

58. Turbulent Arena: Global Effects against Non-State Adversaries, Troy S. Thomas and 

William D. Casebeer, June 2005.

59. Israel’s Attack on Osiraq: A Model for Future Preventive Strikes? Peter S. Ford, 

July 2005.

60. The Art of Peace: Dissuading China from Developing Counter-Space Weapons, 

David O. Meteyer, August 2005.
194

 

61. Biowarfare Lessons, Emerging Biosecurity Issues, and Ways to Monitor Dual-Use 

Biotechnology Trends in the Future, Helen E. Purkitt, September 2005.

62. International Security Negotiations: Lessons Learned from Negotiating with the 

Russians on Nuclear Arms, Michael O. Wheeler, February 2006.

63. Information Warfare Arms Control: Risks and Costs, Maxie C. Thom, March 2006.

64. Strategic Culture and Violent Non-State Actors: Weapons of Mass Destruction and 

Asymmetrical Operations Concepts and Cases, James M. Smith, Jerry Mark Long, and 

Thomas H. Johnson, February 2008.

65. Chinese Perceptions of Traditional and Non-Traditional Security Threats, Susan L. 

Craig, March 2008.

66. Global Insurgency Strategy and the Salafi Jihad Movement, Richard H. Shultz, April 

2008.

67. Conventional Arms Control and American Policy in the 21st Century, Jeffrey D. 

McCausland, December 2010.

68. Qualitative Considerations of Nuclear Forces at Lower Numbers and Implications 

for Future Arms Control Negotiations, Jeffrey A. Larsen, Justin V. Anderson, Darci 

Bloyer, Thomas Devine IV, Rebecca Davis Gibbons, Christina Vaughn, July 2012.

69. Extended Deterrence and Allied Assurance: Key Concepts and Current 

Challenges for U.S. Policy, Justin V. Anderson, Jeffrey A. Larsen, Polly M. 

Holdorf, September 2013.
195

 

UNITED STATES AIR FORCE ACADEMY

Lieutenant General Michelle D. Johnson

Superintendent

Brigadier General Andrew P. Armacost

Dean of the Faculty

HEADQUARTERS, US AIR FORCE

STRATEGIC PLANS AND POLICY DIVISION

Colonel Thomas Summers

Chief

USAF INSTITUTE FOR NATIONAL SECURITY STUDIES

Dr James Smith

Director

Ms Polly Holdorf

Analyst/Editor

Major John Zielinski

Deputy Director

Ms Diahn Langford

Budget Technician

USAFA GRAPHICS

Cover Design