China’s Air Defense Identification Zone
(ADIZ)
Ian E. Rinehart
Analyst in Asian Affairs
Bart Elias
Specialist in Aviation Policy
January 30, 2015

Congressional Research Service
7-5700www.crs.gov
R43894

China’s Air Defense Identification Zone (ADIZ)

Summary
In November 2013, the People’s Republic of China (PRC, or China) announced that it would
establish an “East China Sea Air Defense Identification Zone (ADIZ),” covering a large swath ofairspace over the East China Sea, including over small islands that are the subject of a territorial
dispute among Japan, the PRC, and Taiwan. Beijing did not formally consult with other countries
prior to the announcement, and its initial statement seemed to warn that China might use force
against aircraft that did not follow its ADIZ guidelines. Senior officials from the United Statesand East Asian countries criticized China’s action and raised concerns that the new ADIZ could
escalate tensions surrounding the territorial dispute and even lead to conflict.
Some key considerations for Congress are the potential for military conflict in the East China Sea,
escalation of tensions over the territorial dispute, challenges to the U.S.-Japan alliance, and theimpact on U.S.-China relations, including military-to-military exchanges.
An ADIZ is an area of airspace beyond a country’s sovereign territory within which the country
requires the identification, location, and air traffic control of aircraft in the interest of its national
security. There is no international law that specifically governs ADIZs, although various norms
pertain, especially freedom of navigation. The Convention on Civil Aviation advises that all
nations refrain from the use of weapons against civilian aircraft. The United States was the first
country to establish an ADIZ, which it did in 1950 during the Cold War with the Soviet Union.
There are several possible reasons why the PRC designated its “East China Sea ADIZ” (ECS
ADIZ). The ADIZ appears to be part of an effort by China to challenge Japan’s administration of
the disputed islands, known as Senkaku in Japan, Diaoyu in China, and Diaoyutai in Taiwan. The
ECS ADIZ may also be intended as a means to bolster both China’s own claims to the islands andits justification for opposing U.S. military surveillance activities near its airspace. In the initialperiod after the PRC announcement, the PLA did not take “defensive emergency measures”
against aircraft that ignored the Chinese ADIZ directives.
In addition to criticisms by the U.S. Secretaries of State and Defense that the ECS ADIZ was“destabilizing” and increased the risks of conflict in the region, the United States announced thatit “neither recognizes nor accepts China’s declared East China Sea ADIZ.” As of early 2015, theU.S. military continues to fly aircraft through the zone without notifying China or responding torequests for identification. The Federal Aviation Administration (FAA), however, distributed
China’s requirements for operating in the ECS ADIZ to commercial airlines as part of its routine
dissemination of Notices to Airmen (NOTAMs).
Japan, South Korea, and Taiwan each voiced opposition to China’s designation of the ECS ADIZ,
which overlapped with their pre-existing ADIZs, and have continued normal military practices inthe zone. South Korea requested that China redraw the boundary to remove this overlap, but
Beijing refused the request, prompting Seoul to extend the boundaries of its ADIZ in December
2013. Japan called the PRC’s action an attempt to change the status quo on the Senkaku Islands
by coercion. The U.S.-Japan Mutual Defense Treaty applies to the Senkaku Islands because they
are administered by Japan.
This report analyzes the legal, diplomatic, and security implications of the ECS ADIZ for U.S.
interests. The concluding section briefly discusses some policy options for Congress and for U.S.
policy in general.

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Contents
Introduction...................................................................................................................................... 1
Background and History of ADIZs .................................................................................................. 1
Boundaries of International Airspace and Freedoms of the Air ................................................ 4
PRC’s Announcement of an “East China Sea ADIZ” ...................................................................... 6
PRC’s Announcement of and Rules for an ECS ADIZ.............................................................. 6
Concerns About the Announcement of the ADIZ and the PLA’s Role ...................................... 8
Assessment of Decision Making by Central Leadership ........................................................... 9
PRC Actions in the ECS ADIZ ...................................................................................................... 10
Initial Restraint by PLA in ADIZ Operations .......................................................................... 11
China-Japan Incidents in Mid-2014 ........................................................................................ 12
PRC Rationales for Creating the ECS ADIZ ................................................................................. 13
U.S. Responses .............................................................................................................................. 15
U.S. Guidance to Commercial Airlines ................................................................................... 16
U.S. Official Statements in Response to the ECS ADIZ ......................................................... 17
Reaction of Japan ........................................................................................................................... 18
U.S.-Japan Alliance Relations ................................................................................................. 19
The U.S.-Japan Mutual Defense Treaty and the Senkaku/Diaoyu Islands ........................ 20
Reaction of South Korea ................................................................................................................ 20
Reaction of Taiwan ........................................................................................................................ 22
Implications for U.S. Policy .......................................................................................................... 23
Potential for Conflict ............................................................................................................... 23
Escalation of Tension............................................................................................................... 24
Focus on Japan ........................................................................................................................ 25
Strategic Challenge to U.S. Leadership and Alliances ............................................................ 26
Military-to-Military Exchanges ............................................................................................... 28
Potential Further PRC Actions....................................................................................................... 29
Costs and Consequences for the PRC...................................................................................... 30
Policy Options and Congressional Oversight ................................................................................ 31
Proactive U.S. Policy............................................................................................................... 32
Addressing the ECS ADIZ ...................................................................................................... 33
Clarify Official U.S. Position on the ECS ADIZ............................................................... 33
Lead International Actions ................................................................................................ 33
Oppose Other PRC ADIZs ................................................................................................ 34
Operations to Assert Freedom of Navigation and Overflight ............................................ 35
Accommodation and Assurance of China ......................................................................... 35
Military-to-Military Contacts with China ......................................................................... 35
Strategic Reviews of Policy .............................................................................................. 36
Crisis-Management and Confidence-Building Measures.................................................. 36
Recalibrating the U.S.-Japan Alliance............................................................................... 37
International Rules and Arbitration ................................................................................... 38
Addressing ADIZs at ICAO .............................................................................................. 38
Outlook .......................................................................................................................................... 39

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China’s Air Defense Identification Zone (ADIZ)

FiguresFigure 1. Contiguous U.S. and Canada ADIZ ................................................................................. 2
Figure 2. Air Defense Identification Zones in East Asia ................................................................. 8

TablesTable 1. Comparison of ADIZ Features ........................................................................................... 4

Appendixes
Appendix. Text of ECS ADIZ Announcement............................................................................... 40

Contacts
Author Contact Information........................................................................................................... 41
Acknowledgments ......................................................................................................................... 41

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China’s Air Defense Identification Zone (ADIZ)

Introduction1
This report analyzes the establishment of an air defense identification zone (ADIZ) over the East
China Sea in November 2013 by the People’s Republic of China (PRC, or China), international
responses to that action, its consequences, and related matters of national interest and strategy.
The report examines the legal, military, and diplomatic aspects of China’s ADIZ, with a focus on
U.S. interests and issues of concern to Congress. The most salient issues include bilateralrelations with the PRC, relations with U.S. partners in East Asia, U.S. military posture in the
Asia-Pacific region, and international law (especially regarding freedom of navigation). The 113th
Congress addressed China’s ADIZ in resolutions S.Res. 412 and H.Res. 714, among others. The
114th Congress may choose, in its oversight of U.S. foreign and defense policy and in its
legislative activities, to further shape U.S. responses to China’s ADIZ and related policies.
The PRC’s East China Sea ADIZ has implications for, and is influenced by, numerous otherissues. A partial list of CRS reports on related topics includes:•

CRS Report R42930, Maritime Territorial Disputes in East Asia: Issues forCongress, by Ben Dolven, Mark E. Manyin, and Shirley A. Kan•

CRS Report R42784, Maritime Territorial and Exclusive Economic Zone (EEZ)
Disputes Involving China: Issues for Congress, by Ronald O'Rourke•

CRS Report R42761, Senkaku (Diaoyu/Diaoyutai) Islands Dispute: U.S. Treaty
Obligations, by Mark E. Manyin•

CRS Report R41108, U.S.-China Relations: An Overview of Policy Issues, by
Susan V. Lawrence•

CRS Report RL32496, U.S.-China Military Contacts: Issues for Congress, by
Shirley A. Kan•

CRS Report R41952, U.S.-Taiwan Relationship: Overview of Policy Issues, by
Shirley A. Kan and Wayne M. Morrison•

CRS Report RL33436, Japan-U.S. Relations: Issues for Congress, coordinatedby Emma Chanlett-Avery•

CRS Report R41481, U.S.-South Korea Relations, coordinated by Mark E.
ManyinBackground and History of ADIZs
An ADIZ is a designated area of airspace over land or water within which a country requires theimmediate and positive identification, location, and air traffic control of aircraft in the interest of
the country’s national security.2 While many nations have established one or more ADIZs in theinterest of national security, no international agreement or consensus exists regarding the1

Several sections of this report are based on material authored by retired CRS Specialist in Asian Security Affairs
Shirley Kan.
2
Federal Aviation Administration, Pilot/Controller Glossary (P/CG), an addendum to the Aeronautical Information
Manual, Order JO 7110.10, Flight Services, and Order JO 7110.65, Air Traffic Control, July 24, 2014.

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establishment of or the flight operations and air traffic procedures related to such airspace. ADIZs
are located primarily over waters off coastal nations and often include large swaths of airspacebeyond the boundaries of territorial lands and waters.
In 1948, the U.S. Air Force designated several offshore areas as “active defense areas” or“defense zones.”3 From these, the first ADIZs in the world were established in 1950, under an
Executive Order directing the Secretary of Commerce to exercise security control over aircraft.4
Various defense zones were redesignated as ADIZs.5 The present-day U.S. ADIZs, including thecontiguous U.S. ADIZ (over Atlantic, Pacific, and Gulf of Mexico waters, see Figure 1), theAlaska ADIZ, the Guam ADIZ, and the Hawaii ADIZ, are codified in Title 14, Part 99, of theCode of Federal Regulations, along with the procedural requirements for flights operating inthese designated areas. They are predominantly located over water and typically do not extend to
the shore, leaving a narrow strip of sovereign airspace parallel to the coastline that is not within
the ADIZ.
Figure 1. Contiguous U.S. and Canada ADIZ

Source: National Geospatial Intelligence Agency.
3

Kenneth Schaffel, The Emerging Shield: The Air Force and the Evolution of Continental Air Defense 1945-1960(Washington, DC: Office of Air Force History, United States Air Force), 1991.
4
Harry S. Truman, Executive Order 10197—Directing the Secretary of Commerce to Exercise Security Control Over
Aircraft in Flight, December 20, 1950.
5
At the time, U.S. ADIZs included offshore regions stretching from Maine to North Carolina in the Atlantic, and fromthe U.S.-Canada border to waters off the Baja California in the Pacific. Additionally, several over-land areas were
designated as ADIZs, mostly along the west coast and south of the U.S.-Canada border, but also above interior lands
around Albuquerque, NM, and Knoxville, TN, as part of national security efforts to protect key nuclear researchfacilities in these regions. The over-land ADIZs no longer exist. For a time, portions of the special flight rules area
(SFRA) around Washington, DC, established after the 9/11 attacks in 2001, were designated as an ADIZ, but thisairspace is no longer referred to as such.

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U.S. ADIZ procedures apply to aircraft operating to, from, or within the United States through adesignated ADIZ. The ADIZ procedures do not apply to U.S. military and law enforcement
aircraft. Foreign aircraft, including foreign military aircraft, may generally operate freely within
any portion of an American ADIZ not considered part of domestic airspace without complying
with the regulatory procedures for communications and positive aircraft identification so long as
they do not intend to enter or depart from sovereign U.S. airspace. If however, foreign state or
military aircraft are authorized to operate to or from sovereign U.S. airspace, they generally
would be required to follow all applicable ADIZ procedures when operating in an ADIZ.6
Procedural regulations mandate that all civil aircraft entering an ADIZ maintained by the UnitedStates must be equipped with an operating two-way radio, and in general, unless otherwise
authorized by air traffic control, an operating radar beacon transponder with altitude reporting
capability.7 By regulation, flights operating within an ADIZ must file a flight plan and provide
required information regarding aircraft and operator identification and planned flight trajectory.
Pilots must make position reports to air traffic controllers before entering the ADIZ and uponreaching certain designated reporting points, and must notify controllers of any deviations fromthe flight plan or from air traffic clearance instructions. Additionally, regulations require thataircraft operating in an ADIZ comply with any special security instructions that the Federal
Aviation Administration (FAA) may issue.
The Canadian ADIZ, along with the U.S. ADIZ, is jointly monitored and enforced by the
militaries of both nations. Monitoring and enforcement of ADIZ procedures is the responsibilityof the North American Aerospace Defense Command (NORAD), a bi-national United States andCanadian organization charged with the missions of aerospace warning and aerospace control for
North America.8 In the United States, FAA handles flight plans and requests, while in Canada
NAV CANADA provides air traffic services for aircraft operating within the ADIZ underCanadian civil aviation regulations set forth by Transport Canada. Procedures and regulations areharmonized across both the U.S. and Canadian ADIZ regions.
Among Asian countries, Japan, South Korea, Taiwan, the Philippines, Vietnam, Burma, and India
all established ADIZs more than 20 years ago. Japan’s ADIZ first came into existence during
post-World War II reconstruction to aid Japanese civil air defense initiatives, and Japan codified
the zone in 1969.9 South Korea’s ADIZ came into existence in 1951, during the Korean War, toaid military forces in positive identification of non-hostile civil aircraft. See Table 1 for acomparison of ADIZ features among the United States and selected Asian countries.

6

Examples of foreign state or military aircraft operating to or from the United States may include aircraft carrying
foreign dignitaries, foreign military aircraft participating in joint training exercises, or observation flights conductedunder the multilateral Treaty on Open Skies.
7
See 14 C.F.R. Part 99.
8
See http://www.norad.mil/AboutNORAD/NORADHistory.aspx.
9
Gil Yun-hyung, “The History of Air Defense Identification Zones in Northeast Asia,” Hankyoreh, November 27,
2013.

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Table 1. Comparison of ADIZ Features

Civilian aircraft
required to fileflight plan or
identify?

Military aircraft
required to fileflight plan or
identify?

State aircraft thattransit ADIZ
without entering
sovereign
airspace required
to file flight plan?

United States

Yes

No

No

No

China (PRC)

Yes

Yes

Yes

Yes

Japan

No

No

No

No

South Korea

Yes

Yes

Yes

No

Taiwan (ROC)aYes

UnclearUnclearYes

ADIZ covers
territoryadministered byother country?

Source: 14 C.F.R. 99; PRC Ministry of National Defense announcement; CRS correspondence with Japaneseand South Korean officials; ROC Aeronautical Information Publication.
a.

The ROC has asserted that its official ADIZ covers parts of territory administered by the PRC (on the
Chinese mainland) and by Japan (by one degree of longitude over Japan’s Yonaguni Island).

Boundaries of International Airspace and Freedoms of the Air
Since ADIZs predominantly lie beyond nations’ land borders, their treatment in international law
and international policy debates has been a complex and contentious issue. International civil
aviation matters are generally encompassed in the Convention on International Civil Aviation,commonly known as the Chicago Convention, which the member nations first agreed to in
Chicago, IL, in December 1944 and fully ratified in 1947. While the Chicago Convention does
not address or refer to ADIZs specifically, its first two articles define national sovereignty andterritorial claims with respect to airspace. Specifically, the Chicago Convention maintains thateach nation has complete and exclusive sovereignty with respect to airspace above all recognized
territories, including all land areas and all adjacent territorial waters under its sovereignty,
suzerainty, protection, or mandate.10
The 1982 United Nations Convention on Law of the Sea (UNCLOS) informs present day
international policy discussion regarding territorial waters and, consequently, matters of airspacesovereignty beyond land borders.11 In general, UNCLOS provides that nations maintain exclusive
sovereignty within territorial seas, extending 12 nautical miles (roughly 14 statute miles)
offshore. Additionally, UNCLOS defines “contiguous zones” as additional outer bands extending
to 24 nautical miles (roughly 27.5 statute miles) from shore, in which a nation may exercise
certain controls and enforcement actions to protect itself from infringement of its customs, fiscal,
immigration, or sanitary laws and regulations. Further, UNCLOS allows nations to establish
exclusive economic zones (EEZs), extending as far as 200 nautical miles (roughly 230 statute
miles) offshore, in which a nation can exert control over activities impacting economic resources
including fishing, mining, oil exploration, and pollution. UNCLOS maintains that all nations may
enjoy the freedoms of navigation and overflight within these zones, as well as other
10

International Civil Aviation Organization (ICAO), Convention on International Civil Aviation, Ninth Edition, Doc
7300/9, 2006, http://www.icao.int/publications/pages/doc7300.aspx.
11
See Kay Hailbronner, “Freedom of the Air and the Convention on the Law of the Sea,” American Journal ofInternational Law, 77(3), July 1983, pp. 490-520.

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internationally lawful uses, which in general may include military exercises, reconnaissance, andother civilian and military use.12 The United States has not ratified UNCLOS, unlike China,
Japan, and South Korea.
Most governments contend that transiting vessels and aircraft maintain high seas freedoms inboth contiguous zones and in EEZs, although China and some other nations dispute thisinterpretation.13 China, Brazil, and some other coastal nations contend that they have some rights
to regulate certain military traffic flying above their EEZs.14 In contrast, the United States asserts
the rights of U.S. military aircraft to transit through ADIZs without complying with procedural
regulations established for the ADIZ so long as the aircraft do not intend to enter the nation’s
sovereign airspace and are not otherwise under the guidance of air traffic control.15
China’s assertion of control of international airspace overlying its EEZ and U.S. disagreementwith this assertion played a part in the April 2001 collision of a People’s Liberation Army (PLA,
the official name of the Chinese military) J-8 fighter with a U.S. Navy EP-3 reconnaissanceaircraft over the South China Sea. The mishap resulted in the death of the PLA pilot and thedetention and interrogation of the U.S. Navy crew, which was forced to make an emergency
landing on the PRC’s Hainan Island. (See CRS Report RL30946, China-U.S. Aircraft Collision
Incident of April 2001: Assessments and Policy Implications, by Shirley A. Kan, et al.)Since the boundaries of various established ADIZs extend even farther than limits established for
EEZs, portions of ADIZs clearly lie over international waters and constitute international
airspace. For example, portions of the contiguous U.S. ADIZ extend more than 400 miles
offshore. Additionally, major portions of established ADIZs extend beyond the limits of territorial
seas and are generally not claimed as sovereign airspace except in cases of rare disputes.
Consequently, nations generally have no particular international legal basis to establish
procedural controls over or requirements regarding the movement of aircraft within such airspace.
In contrast, in airspace above territorial seas, international law does not specifically impart any
rights of transit or innocent passage to foreign aircraft.16 Rather, such overflights are made only
upon authorization or agreement of the controlling nation, typically within the context of various
bilateral and multilateral aviation agreements, air service agreements, and open skies agreements.
Many coastal nations provide air traffic services17 beyond their territorial claims and, according toInternational Civil Aviation Organization (ICAO) standards, may do so in a manner consistent
with the procedures established for other airspace under their jurisdictions.18 In other words,
12

Ibid.
For more information, see CRS Report R42784, Maritime Territorial and Exclusive Economic Zone (EEZ) Disputes
Involving China: Issues for Congress, by Ronald O'Rourke.
14David A. Welch, “What’s an ADIZ?” Foreign Affairs, December 9, 2013, available at
http://www.foreignaffairs.com/articles/140367/david-a-welch/whats-an-adiz.
15Peter A. Dutton, “Caelum Liberum: Air Defense Identification Zones Outside Sovereign Airspace,” The American
Journal of International Law, 103(4), October, 2009, pp. 691-709.
16
Kay Hailbronner, “Freedom of the Air and the Convention on the Law of the Sea,” American Journal ofInternational Law, 77(3), July 1983, pp. 490-520.
17
Air traffic services include aircraft separation and air traffic control, air traffic management, en route weather reports,
flight tracking, and other services primarily focused on flight safety.
18
See International Civil Aviation Organization, International Standards: Annex 2 to the Convention on International
Civil Aviation, Rules of the Air, Tenth Edition, July 2005, 2.1 Territorial application of rules of the air; Kay(continued...)13

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nations are not required to distinguish between sovereign domestic airspace and international
airspace for those aircraft to which they provide services, including aircraft transiting through thedesignated ADIZ. In general, nations harmonize their air traffic procedures and flight rules acrossall airspace, regardless of whether such services are provided in sovereign airspace or airspaceover the high seas. ICAO has designated Flight Information Regions (FIRs) to determine what
airport in what country will provide air traffic services in any given location. The entire world isdivided into FIRs, so that civilian flights will always have a designated air traffic controller.
Many FIRs extend into airspace over the high seas.
ICAO has adopted specific international standards with respect to air traffic rules, but nations
may choose to ignore, augment, or modify this general guidance. ICAO provides no specificstandard or guidance with respect to the establishment of ADIZs, or air traffic rules or procedures
for aircraft operating within designated ADIZs. There are no formal international agreements
governing the creation of an ADIZ or procedural controls implemented within any ADIZ.19 Somelegal scholars have questioned the international legal basis for establishing ADIZs and havecriticized the practice.20
While the Chicago Convention and ICAO are silent with respect to the establishment of ADIZs,
the Chicago Convention offers specific guidance with respect to military engagement of civil
aircraft, a key component of enforcing procedures established with respect to both sovereign
airspace and ADIZs. The Chicago Convention advises that all nations should refrain from the useof weapons against civil aircraft, and in cases involving the interception of civilian aircraft,
efforts should be made so as not to endanger the safety of the aircraft and the lives of the persons
on board. Notwithstanding such protections, the Chicago Convention expressly acknowledges
that a nation is entitled to intercept a civil aircraft overflying its territories without authorizationand force it to land if there are reasonable grounds to conclude that the aircraft is operating inviolation of established international civil aviation agreements. The Chicago Convention,
however, does not explicitly address the interception of civilian aircraft operating outside
sovereign airspace.

PRC’s Announcement of an “East China Sea ADIZ”
PRC’s Announcement of and Rules for an ECS ADIZOn November 23, 2013, the PRC announced that its “East China Sea Air Defense Identification
Zone” (ECS ADIZ) would be effective at 10:00 AM that same day.21 (See the Appendix for the(...continued)
Hailbronner, “Freedom of the Air and the Convention on the Law of the Sea,” American Journal of International Law,
77(3), July 1983, pp. 490-520.
19
David A. Welch, “What’s an ADIZ?” Foreign Affairs, December 9, 2013, available at
http://www.foreignaffairs.com/articles/140367/david-a-welch/whats-an-adiz.
20
See Ivan L. Head, “ADIZ, International Law, and Contiguous Airspace,” Alberta Law Review, 3, 1964, p. 196; Kay
Hailbronner, “Freedom of the Air and the Convention on the Law of the Sea,” American Journal of International Law,
77(3), July 1983, pp. 490-520; Peter A. Dutton, “Caelum Liberum: Air Defense Identification Zones Outside Sovereign
Airspace,” The American Journal of International Law, 103(4), October, 2009, pp. 691-709.
21
Before September 2013, the PLA indicated that it was considering a plan to declare a new ADIZ (“PLA Plans to
Establish Air Defense Identification Zone,” Kanwa Defense Review, Toronto, August 1, 2013). Additionally, reports(continued...)Congressional Research Service

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full statement.) The PRC cited its domestic laws as the legal basis.22 The proclamation included amap of the parameters for the ECS ADIZ, which extends over a large part of the East China Sea,
beyond the FIRs managed by Chinese air traffic controllers. The ECS ADIZ asserted coverage ofthe airspace over the Senkaku Islands, which are administered by Japan and claimed by the PRC
as the Diaoyu Islands and by Taiwan as the Diaoyutai Islands. In addition, the PRC’s ECS ADIZ
asserted coverage of the airspace over a submerged rock over which the Republic of Korea(ROK) asserts administration and on which it built an ocean research station, a rock that the ROK
calls Ieodo and the PRC calls Suyan Rock. Moreover, the ECS ADIZ overlaps with the existing
ADIZs of Japan, ROK, and Taiwan. Furthermore, the PRC Ministry of National Defense (MND)
issued rules for the ECS ADIZ that apply generally to aircraft flying in the ECS ADIZ, regardlessof whether the aircraft intends to enter the PRC’s airspace. The rules require flight plan
identification, radio identification, transponder identification, and logo identification. The rules
warn that “China’s armed forces will adopt defensive emergency measures to respond to aircraftthat do not cooperate in the identification or refuse to follow the instructions.”23(...continued)
from prior years indicate that the PRC was conducting research about ADIZs (Peter A. Dutton, “Caelum Liberum: Air
Defense Identification Zones Outside Sovereign Airspace,” The American Journal of International Law, 103(4),October, 2009, pp. 691-709).
22
Specifically, the PRC cited the PRC National Defense Law of March 14, 1997; PRC Civil Aviation Law of October30, 1995; and PRC Basic Flight Regulations of July 27, 2001.
23
Xinhua, November 23, 2013.

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China’s Air Defense Identification Zone (ADIZ)

Figure 2. Air Defense Identification Zones in East Asia

Source: Congressional Research Service.

Concerns About the Announcement of the ADIZ and the PLA’s
Role
Asia security expert Douglas Paal and other analysts have argued that the PRC’s announcementof the ECS ADIZ was “clumsy,” sudden, and lacked careful consideration of the costs to the
PRC’s external economic, diplomatic, and military engagements, as well as to its attempts toCongressional Research Service

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cultivate an image of a peacefully rising power.24 Chinese officials and scholars defended China’s
right to establish an ADIZ, but officials from the United States, Japan, South Korea, and othercountries strongly protested the move (see later sections). The announcement came shortly before
a high-profile trip to Japan, South Korea, and China by U.S. Vice President Joseph Biden in early
December 2013 and just before the planned third meeting of the PLA’s Defense Strategic
Dialogue with the ROK military.25
The way in which the rules were announced appeared to create uncertainty about theirimplementation. On the same day as the announcement, the MND spokesman made inconsistentstatements. He noted that the ECS ADIZ is beyond the national airspace but also claimed a role
for the ECS ADIZ in safeguarding state “sovereignty,” as well as territorial land and air security,
and aviation order. Although the declared rules were to apply to all aircraft entering the ECS
ADIZ, he said that normal flights by foreign airlines in the ECS ADIZ would not be affected.26
The PLA insisted that the PRC has a right to set up an ADIZ after foreign precedents. The PRC
Ministry of Foreign Affairs (MFA) defended the PLA’s warning to foreign civilian aircraft andrepeated that normal flights of foreign airlines in the ECS ADIZ would not be affected.27 In
January 2014, a PLA Air Force major general, professor, and author acknowledged“misunderstanding” by the Chinese public about whether the PLA Air Force was compelled todirect away or even shoot down aircraft flying in the ECS ADIZ.28

Assessment of Decision Making by Central Leadership
Although there were indications that the ECS ADIZ regulations were proposed by the PLA and to
be implemented by the PLA, the announcement reportedly reflected a top-level decision by Xi
Jinping.29 At the same time that the MND explained the new ADIZ’s rules, individuals identified
as experts by the PLA presented legal and other justifications in official media, a sign of advance
preparation rather than a sudden step.30 The MND first announced the ECS ADIZ in a high-level“PRC Government Statement.” This treatment is consistent with the policy having been the resultof a top-level decision. As the authorized administrative organ, the MND then issued its statement
and rules for the ECS ADIZ. On November 27, 2013, the PLA Navy’s newspaper, People’s Navy,published an article by the Director of the Research Office of Maritime Security Policy of theNaval Military Art Studies Institute, saying that the ECS ADIZ is a major decision of the CPC
Central Committee, the State Council, and the Central Military Commission (CMC).31 In another24
Esther Teo, “How China Bungled the Launch of Its Air Zone,” Straits Times, Singapore, November 30, 2013;
Douglas Paal, “Contradictions in China’s Foreign Policy,” Carnegie Endowment, December 13, 2013.
25
The official China National Television (CNTV) reported on the meeting on November 28, 2013. The PRC MFA
stated at a news conference on November 28 that the third PRC-ROK Defense Strategic Dialogue was previously
scheduled.
26
PRC MND, “Response to Questions on the Establishment of the ECS ADIZ,” November 23, 2013.
27
PRC Ministry of Foreign Affairs, transcript of news conference, November 26, 2013.
28
PLA Air Force Major General Qiao Liang, “Only by Becoming Powerful Can China Be Firm,” Military Digest,
January 2014, translated by Ryan Martinson, China Maritime Studies Institute, U.S. Naval War College.
29
Jane Perlez, “Chinese Leader’s Rise Came with New Attention to Dispute with Japan,” New York Times, December
2, 2013.
30
For example, articles appeared in both PRC government and military media: “Military Experts Explain China’s Air
Defense Identification Zone,” “Air Defense Identification Zone a Strategic Decision,” Xinhua, November 23, 2013;“The Legitimate and Lawful Move of Safeguarding National Sovereignty and Security: Legal Interpretation of China’s
Establishment of the East China Sea Air Defense Identification Zone,” Liberation Army Daily, November 24, 2013.
31
Ren Xiaofeng, “A Major Measure for Protecting the Sovereignty and Security of National Territory and Territorial(continued...)Congressional Research Service

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sign that the announcement was not only a PLA decision, PLA spokesmen and MFA spokesmen
issued similar statements to reporters to defend the ECS ADIZ.
Since Xi Jinping completed his formal ascension to the top positions of power in 2012-2013, the
PRC has continued an apparent trend of coordinated actions asserting its claims in the East andSouth China Seas.32 Xi Jinping reportedly has led a Maritime Security Leading Small Group since
early 2012.33 A top-level report delivered at the November 2012 18th Party Congress called for
China to better exploit maritime resources, safeguard maritime rights and interests, and build
China into a maritime power. In April 2013, the PRC issued the 2012 White Paper on the armed
forces, entitled “Diversified Employment of China’s Armed Forces,” that focused more narrowly
than in past White Papers on the centrality of maritime disputes in the PRC’s perceived security
situation and signaled a hardening of its stance to “safeguard” maritime territory and rights with agreater willingness to use force to advance its claims.34 In July 2013, Xi held a meeting of the
Politburo at which he called for building China’s “maritime power” comprehensively in political,
economic, military, and technological fields. Xi has articulated the PRC’s position on its ECSADIZ to various parties, including Vice President Biden.35 The announcement was consistent
with PRC propaganda’s portrayal of Xi as a proactive leader who has “new initiatives.”

PRC Actions in the ECS ADIZ
PLA actions in the ECS ADIZ have been largely in line with international norms regarding
ADIZs, with a few exceptions. Despite initial concerns that the PLA would conduct assertive
interceptions of foreign aircraft that did not comply with the identification requirements, there
were few incidents in late 2013 and early 2014. In mid-2014, however, PLA Air Force aircraft
flew in immediate proximity to Japanese surveillance aircraft on multiple occasions, according toJapanese reports. In October 2014, U.S. Commanders of the Pacific Air Forces and Navy’s
Seventh Fleet said that the PLA’s intercepts in its ECS ADIZ generally have been professional.36(...continued)
Airspace—An Interpretation of China’s Demarcation of the East China Sea Air Defense Identification Zone,” Renmin
Haijun [People’s Navy], November 27, 2013.
32
At the 18th Party Congress in November 2012, Hu Jintao transferred to Xi Jinping both positions of Communist Partyof China (CPC) General Secretary and Central Military Commission (CMC) Chairman. In March 2013, the 12th
National People’s Congress announced Xi’s position as the PRC President. See CRS Report R43303, China’s Political
Institutions and Leaders in Charts, by Susan V. Lawrence.
For more information and analysis on maritime issues, see CRS Report R42930, Maritime Territorial Disputes in East
Asia: Issues for Congress, by Ben Dolven, Mark E. Manyin, and Shirley A. Kan and CRS Report R42784, Maritime
Territorial and Exclusive Economic Zone (EEZ) Disputes Involving China: Issues for Congress, by Ronald O'Rourke.
33
Jane Perlez, “Chinese Leader’s Rise Came with New Attention to Dispute with Japan,” New York Times, December
2, 2013.
34“The Diversified Employment of China’s Armed Forces,” Information Office of the PRC State Council, April 16,
2013, http://news.xinhuanet.com/english/china/2013-04/16/c_132312681.htm.
35Unnamed Administration officials who accompanied Vice President Biden to Asia told reporters in a briefing on
December 4, 2013, in Beijing, that Xi Jinping was equally comprehensive in laying out China’s perspective on thezone, view of territorial disputes, and broader regional tensions; Xinhua reported on December 4, 2013, that Xi Jinping
reiterated the PRC’s “principled” position on the ECS ADIZ. Xinhua did not mention the ECS ADIZ in Vice President
Li Yuanchao’s or Premier Li Keqiang’s talks with Vice President Biden.
36
Audrey McAvoy, “U.S. General: Most East China Sea Interactions Safe,” Associated Press, October 9, 2014; Isabel
Reynolds, “U.S. Commander Seeks to Make Chinese Military Encounters Boring,” Bloomberg, October 24, 2014.

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Initial Restraint by PLA in ADIZ Operations
Although the PLA Air Force reportedly has monitored U.S. and Japanese military aircraft thatentered the ECS ADIZ, the PLA’s enforcement of the ECS ADIZ generally has appeared to be
restrained, according to U.S. defense officials. Concerns that the PLA would forcefully administer
the zone, as the initial announcement appeared to forewarn, were not borne out in late 2013 andearly 2014. For instance, the PLA did not respond to the two U.S. Air Force B-52 bombers thatflew on November 25, 2013, from Guam through the PRC’s ECS ADIZ without informing
Beijing, according to a Pentagon spokesman.37 Following the PRC’s announcement, in lateNovember 2013 Japan and South Korea also flew military aircraft in the PRC’s ECS ADIZ
without notifying PRC authorities, but both countries indicated that they detected no response
from the PLA.38 The PLA Air Force later said that it patrolled its ECS ADIZ on November 28-29,
2013, and detected U.S and Japanese military aircraft.39 A Japanese defense official said in
January 2014 that the PLA had not taken actions against Japanese military aircraft flying in thezone.40 The U.S. Pacific Command (PACOM) Commander, Admiral Samuel Locklear, said that
there had not been a significant change in U.S. military interactions with the PLA and that the
PLA had acted professionally.41 After its announcement, the PRC assured commercial airlines that
normal flights of foreign airlines would not be affected, despite the broad warnings in the ECSADIZ rules.
There are several possible explanations for the PRC’s apparent restraint in enforcing its ADIZ
regulations. The PLA may have been surprised by the B-52 flights that occurred within days of
the ECS ADIZ announcement and may have felt unprepared to confront the prompt U.S. reaction.
The PLA Air Force and PLA Navy might have been inadequately prepared at the operational levelto implement the ECS ADIZ.42 The PLA senior command might not delegate authority to thelower commands for routine operations or for risky ECS ADIZ enforcement that could cause
crashes, or centralized control might not be sufficiently effective.43 The PLA might lack adequate
capabilities, including ground-based air surveillance, to monitor fully the whole ECS ADIZ. Still,
37

Phil Stewart and David Alexander, “Defying China, U.S. Aircraft Fly Over East China Sea Without Notification,”
Reuters; Julian Barnes and Jeremy Page, “U.S. Directly Challenges China’s Air Defense Zone,” Wall Street Journal,
November 26, 2013.
38
Chief Cabinet Secretary Yoshihide Suga said Japan did not detect a response from China, and South Korea’s military
reported that its aircraft flying in the ECS ADIZ noticed no response from the PLA (Kyodo and AFP, November 28,2013). Kyodo (November 30, 2013) quoted Defense Minister Itsunori Onodera as saying there were no remarkabledevelopments.
39“PLA Main Battle Aircraft Carry Out Normalized Patrols in the East China Sea Air Defense Identification Zone,”
Xinhua, November 28, 2013; “China Air Force Identifies and Collects Evidence of Foreign Military Aircraft Entering
Our Air Defense Identification Zone in East China Sea,” Xinhua, November 29, 2013.
40“No Reports of Warnings Against SDF Aircraft,” NHK Online, Tokyo, January 24, 2014.
41
Defense Department, Pacific Command Commander Admiral Samuel Locklear III, News Conference, January 23,
2014; News Conference, Tokyo, Japan, February 5, 2014.
42
The Global Times (sponsored by the official People’s Daily) published an editorial on November 28, 2013, which
conceded that “China’s ADIZ withstood the test but we failed in offering a timely and ideal response as we have beeninundated with an inconceivably large amount of information that is adverse to the new zone and will probably evenundermine the image of our military forces in this transient Internet age. Therefore, Chinese authorities must makespeedy reactions to various emergencies and challenges, and delegate such power to relevant departments and officials,
who should meanwhile assume more responsibility to cope with sensitive issues.”
43
The Liberation Army Daily reported on January 23 and 28, 2014, that the PLA Air Force plans in the future to use
early warning aircraft to command directly an air combat group of fighters, bombers, and tankers to manage the ECSADIZ efficiently.

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the Chief of Staff of the Air Force, General Mark Welsh, said in December 2013 that the PLA has
the capability and equipment to operate in the zone.44 An unclassified U.S. Air Force assessment
found that China is not likely to maintain a constant presence over the East China Sea withfighters or support aircraft, but the PLA will use ground-based radar coverage to maintainawareness in the ECS ADIZ.45 The report asserted that the PLA will monitor and manage the ECSADIZ with shared responsibility among coastal units, command posts in the Nanjing Military
Region on the east coast, and centralized commands in Beijing.
Another possible explanation is that the PRC could be pursuing a long-term strategy to alter the
status quo in its favor while seeking to avoid a backlash from neighboring countries or the UnitedStates. In early 2014, PRC Foreign Minister Wang Yi insisted that Beijing respects Washington’s
legitimate interests in the Asia-Pacific region and cited Xi Jinping as saying that the Pacific
Ocean is large enough for China and the United States.46 The PRC may be seeking to advance its
position over the long term after a short spike in tension, leaving a new status quo with the ECSADIZ in place.47 The PRC would acquire strategic advantage by asserting a maximalist position,then seeming to back down, while preserving some incremental gain—akin to a “ratchet” effect.
According to this theory, the PRC would project a calm image and justify the ECS ADIZ as a“reasonable” step to which foreign nations should not object.48 If there is an accident, crisis, orloss of life, Beijing could then blame Tokyo, Seoul, Taipei, or Washington.49 The ECS ADIZ did
not involve aggressive actions by the PLA in the initial phase, but some observers view thedeclaration of the ADIZ as another of the PRC’s incremental law-enforcement and military
actions, especially since 2005, to advance its national interests at the expense of other countries.50

China-Japan Incidents in Mid-2014
In May and June 2014, Chinese fighter jets flew extremely close to Japanese propeller-driven
reconnaissance airplanes in the overlapping area of the Chinese and Japanese ADIZs on several
occasions. The Japanese Minister of Defense called these intercepts “extremely dangerous
44

Aaron Mehta, “Chinese Air Defense ID Zone Shows Need for Communication,” Defense News, December 11, 2013.
Department of the Air Force, “Broad Trends in Chinese Air Force and Missile Modernization,” Statement of Lee
Fuell, Presentation to the U.S.-China Economic and Security Review Commission, January 30, 2014.
46
PRC MFA, Foreign Minister Wang Yi’s Interview with Al-Jazeera, January 10, 2014.
47
For example, one commentator writes that “China’s leaders know that time and global trends are on their side as longas nothing goes disastrously wrong domestically and as long as they do not actually provoke a war with Japan, the U.S.,
or any other country (Jamil Anderlini, “Beijing Plays a Longer Game With Its Air Defense Zone,” Financial Times,
November 27, 2013).
48
For example, on November 27, 2013, the Hong Kong-based China News Agency quoted Professor Meng Xiangqing
at the Strategic Research Institute of the PLA’s National Defense University as saying that “the United States and Japan
should recognize that China’s setting up the East China Air Identification Zone was already an established fact.”
Former Ambassador Winston Lord notes that China does not shy from provocation and counts on eventual foreign
forbearance, quoted in Leslie Gelb, “Time to Get Tough With China,” Washington Daily Beast, December 8, 2013.
49
People’s Daily published an article, “China ECS ADIZ Makes Its Point,” on December 9, 2013, arguing that “within
3 days of China’s announcement of the ECS ADIZ, America and Japan had sent a succession of warplanes into thezone, and this is the real cause of the increase in the tension in the area.”
50
There have been numerous assertive actions by the PRC to make territorial or other nationalist claims since 2005,
although incidents have occurred for decades and the PRC has not been the only party to assert claims. On November
29, 2013, the International Herald Leader (published by the official Xinhua agency) published an article called“China’s ‘Three Steps’ to Strengthen Control of the Diaoyu Islands,” which discussed the ECS ADIZ as a part of astrategy of so-called “salami slicing.”
45

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actions” and said that his government had lodged stern protests with Beijing.51 The PRC MND
disputed that the flybys were dangerous and defended the actions as legitimate enforcement of the
ECS ADIZ.52 The presence of Chinese-Russian military exercises in nearby waters during the
May incidents may have increased China’s sensitivity to Japanese surveillance activities.
A prior incident with Japan occurred on January 10, 2013, when the PLA reportedly scrambled
two J-10 fighters after Japan sent F-15 fighters to observe a PLA Air Force Y-8 early warning
aircraft flying over oil and gas fields in the East China Sea.

PRC Rationales for Creating the ECS ADIZ
One question regarding the PRC’s ECS ADIZ announcement is whether it was primarily apolitically symbolic statement or instead represented a plan to advance the PRC’s administrative
control of disputed territory and/or its military anti-access/area-denial (A2/AD) strategy.53 PRC
official media stated that “in fact, prior to the announcement of the air defense identification zone,
China already instituted early-warning mechanisms and adopted specific air traffic control
measures with regard to the islands over which it claims jurisdiction, including the Diaoyu
Islands, and the East China Sea airspace over the related waters.”54 The PLA Air Force has
managed air traffic control for the PRC, largely for security reasons, and long before announcing
an ECS ADIZ, the PLA scrambled fighters to intercept foreign aircraft, including U.S.
reconnaissance aircraft (such as the PRC’s April 2001 interception of a U.S. Navy EP-3 plane that
resulted in a collision and crisis).
The ECS ADIZ announcement could be primarily a symbolic political statement. An expert on
the PLA Navy at the U.S. National War College said that the ECS ADIZ is more a “politicaldeclaration than anything that contributes materially to the military capability to carry out” an
A2/AD strategy.55 The PRC leadership could have proclaimed the ECS ADIZ for political reasons
to ameliorate internal pressure or struggles inside China.56 However, PRC leaders agree generally
on territorial and maritime claims, especially against Japan. Also, the PRC took assertive or
aggressive actions to advance its claims before and after the transition of power from Hu Jintao to
Xi Jinping as the top leader in late 2012 to early 2013. There were no nationalistic, violent antiJapan protests surrounding the ECS ADIZ announcement, unlike the rare protests that erupted
during similar periods of heightened tensions with Japan in September 2010 and September 2012.
The absence of protests may have been a sign that Chinese leaders did not seek to rally domestic
political forces. Comments in China about the ECS ADIZ on the Internet were generally muted.57
51

Martin Fackler, “Japan Protests Chinese Flybys over East China Sea,” New York Times, June 11, 2014.

52“” PRC Ministry of National Defense, May 25, 2014,
http://news.mod.gov.cn/headlines/2014-05/25/content_4511503.htm.
53
An anti-access/area-denial (A2/AD) strategy aims to use actions to slow or keep farther away the foreign forces inmovement to a theater of operations and to impede foreign freedom of operations in maneuvering within a theater.
54
Yu Zhirong (Research Fellow of the China Ocean Development Research Center), “Urging Japan Not to Make Lightof Civil Aviation Aircraft Safety,” International Herald Leader, December 6, 2013.
55
Bernard Cole quoted in Wendell Minnick, “China’s Air Zone Part of Anti-access Strategy,” Defense News,
December 9, 2013.
56
Russell Moses, “Why Xi Jinping’s Done Little to Sell China’s Air Defense Zone,” Wall Street Journal, December 2,
2013; Robert Kaplan, “Why Is China Really Provoking Its Neighbors?” RealClearWorld.com, February 13, 2014.
57
Jamil Anderlini, “Spat over Air Space Lost on Ordinary Chinese,” Financial Times, December 1, 2013.

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13China’s Air Defense Identification Zone (ADIZ)Over the longer run, Xi could be using the formal ECS ADIZ as a mechanism to push the PLA to
higher readiness or alert levels as well as to promote joint operations. Indeed, in asserting that the
PLA Air Force scrambled fighters in late November to patrol the ECS ADIZ, the PLA Air Forcespokesman specifically stated that both the PLA Air Force and PLA Navy would be on constantalert and jointly safeguard the PRC’s ECS ADIZ. Such an effort is consistent with the widelyreported exhortations (particularly since 2013) in the defense-related White Paper and innumerous articles that stressed to the PLA that it should promote realistic training to prepare for
actual combat and should develop stronger capabilities, including in maritime actions.58 The“Decision” of the Third Plenum of November 2013 stipulated that, as part of military reform, the
PLA should “restructure and rationalize border, sea, and air defense management systems andmechanisms.”59
One analyst assessed the ECS ADIZ announcement as part of the PRC’s international legal
assertion of EEZ claims and noted that the eastern edge of the PRC ECS ADIZ closely follows
the eastern edge of the PRC’s claim to an extended continental shelf in the East China Sea.60
The ECS ADIZ could have been intended to elicit an overreaction from Japan, so that the PRC
could advance its interests while claiming to be a target of Japanese provocations (see section“Focus on Japan”). Indications are that the PRC’s administration of its ECS ADIZ has targeted
Japanese aircraft in particular, rather than U.S., South Korean, Taiwanese, or other foreign
aircraft. The MND justified extending the PRC’s ECS ADIZ to within 130 km of a “certain
country,” apparently Japan, by pointing to that country’s establishment of an ADIZ in 1969 thatwas 130 km from the coast of the PRC. As of January 2015, the Japanese military has not taken
any actions in the contested airspace that have drawn criticism from the international community.
Another motivation for the ECS ADIZ announcement could have been a desire for parity withJapan and other countries that have established ADIZs and have scrambled fighters in response toforeign aircraft. Japan’s frequent scrambling of fighters could have increased the PRC’s interest insetting up its own ADIZ. The PRC’s aircraft, including official, non-PLA planes, haveencountered fighters scrambled by the Japanese Air Self-Defense Force (ASDF).61 Japan’s ASDF
scrambled fighters 415 times to respond to PRC aircraft from April 2013 to April 2014, anincrease by 109 sorties from the previous year.62 Relatedly, Beijing might have set up the ECSADIZ for prestige. A Major General in the PLA Air Force asserted that the PRC set up its ECSADIZ for political-strategic significance as a “great power” because, according to the Major
General, an ADIZ is an important symbol of modern countries with air defense capability.63
Tested by the ECS ADIZ, the PLA Air Force will become stronger, he stressed. In this view, the58
While the call for the PLA to train for realistic combat is not new, Xi Jinping seems to stress realistic combatreadiness above other objectives. The Liberation Army Daily, on February 24, 2014, noted that combat capability has
become the only criterion.
59
CPC Central Committee, “Decision on Deepening of Reforms,” Xinhua, November 15, 2013.
60
Peter Dutton, Testimony at House Foreign Affairs Committee Hearing on China’s Maritime Disputes in the East andSouth China Seas, January 14, 2014.
61
In December 2012, the ASDF scrambled fighters to respond to a China Maritime Surveillance (CMS) maritime
patrol plane that flew over the Senkaku/Diaoyu Islands, in addition to patrols at sea.
62
“Statistics on Scrambles Through Fiscal Year 2013,” Japan Ministry of Defense, Joint Staff Press Release, April 23,
2014.
63
PLA Air Force Major General Qiao Liang, “Only By Becoming Powerful Can China Be Firm,” Military Digest,
January 2014, translated by Ryan Martinson, China Maritime Studies Institute, U.S. Naval War College.

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lack of consultation with other countries is consistent with the PRC’s position, as seen in its 2012
Defense White Paper, that it is a major power safeguarding its rights.
Another possible motivation for declaring the ECS ADIZ is the PLA’s objection to U.S. Navy and
Air Force reconnaissance flights, which PLA officials have identified as an “obstacle” in the
military relationship with the United States. A PLA Navy expert noted the ECS ADIZ provides
the “legal” authority to track the reconnaissance planes, even though the PLA may not “shootthem down.”64 The U.S. military maintains that its flights operate legitimately in international
airspace, not the PRC’s airspace.

U.S. Responses
Promptly after the PRC announced the ECS ADIZ on November 23, 2013, Defense Secretary
Hagel called the development a destabilizing attempt to alter the status quo, stated that theannouncement would not change U.S. military operations, and reaffirmed that the U.S.-Japan
Mutual Defense Treaty applies to the Senkaku Islands.65 Secretary of State John Kerry expressed
concern that the unilateral action was an attempt to change the status quo in the East China Sea
and would increase tensions and create risks of an incident. He also stated that the United States
does not recognize efforts by any country to apply its ADIZ procedures to foreign aircraft notintending to enter national airspace nor does the United States apply its ADIZ procedures toforeign aircraft not intending to enter U.S. airspace. Secretary Kerry urged the PRC not to
implement its “threat” to take action against aircraft that do not identify themselves or obey
orders from the PRC. He urged the PRC to exercise restraint.66 The White House called the PRC’s
announcement an “escalatory development” that increased tensions.67
U.S. concerns focus in part on the way in which the PRC set up its ECS ADIZ. A senior official
on the U.S. National Security Council (NSC) staff said that “we [the Obama Administration] saw
it as a provocative and escalatory act that increased tensions in the region and reduced theprospect for diplomacy. Regardless of whether China had a right to establish the ADIZ, the way
China did it was dangerous.”68 The PRC’s ECS ADIZ overlaps with other ADIZs, raising thepotential for accidents or incidents that could involve interceptions by fighters. The United Statesreceived less than one hour’s formal notice before the PRC’s ECS ADIZ announcement.69
Two days after the PRC’s declaration of the ECS ADIZ, the U.S. Navy announced the start of theAnnual Exercise (AnnualEx) 2013 involving the carrier strike group led by the USS George
Washington in training with Japan’s Maritime Self-Defense Force. The U.S. Air Force flew two
B-52 bombers from the U.S. territory of Guam on a training flight into the ECS ADIZ without
64
Liu Ziwei, “An Air Defense Identification Zone is Not the Same as Territorial Airspace, and No One Should Confuse
Them,” Global Times, November 25, 2013.
65“Statement by Secretary of Defense Chuck Hagel on the East China Sea Air Defense Identification Zone,” U.S.
Defense Department, November 23, 2013.
66
State Department, “Statement on the East China Sea Air Defense Identification Zone,” November 23, 2013.
67
Steve Holland, “U.S. Voices Strong Concern to China over East China Sea Tensions,” Reuters, November 23, 2013.
68
Yoichi Kato, “INTERVIEW/ Evan Medeiros: China’s Attempt to Isolate Japan Worsens Bilateral Relations,” Asahi
Shimbun, April 6, 2014.
69
CRS consultations in November 2014; Simon Denyer, “Obama’s Asia Rebalance Turns into Headache as China,
Japan Relations Spiral Down,” Washington Post, January 23, 2014.

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informing China. A Pentagon spokesman said that “we have conducted operations in the area of
the Senkakus. We have continued to follow our normal procedures, which include not filing flightplans, not radioing ahead, and not registering our frequencies.”70 Although the bombers’ flightreportedly had been planned far in advance, going through with the flight conveyed continuity ofoperations, sustained support for Japan, and non-compliance with the PRC’s ECS ADIZ. In
August 2014, a PLA fighter aircraft intercepted at close range a U.S. P-8 surveillance aircraft ininternational airspace near China’s southeastern coast, providing further evidence that the U.S.
military continues its normal pattern of operations.71

U.S. Guidance to Commercial Airlines
After the PRC first announced the ECS ADIZ, it distributed its regulations internationally as a
Notice to Airmen (NOTAM), which is a notice disseminated by an aviation authority to alert
pilots of potential hazards that could affect the safety of their flight.72 Regarding commercial
aviation, the State Department said on November 29, 2013, that the United States generally
expects that U.S. carriers operating internationally will follow NOTAMs issued by foreigncountries. The State Department also said that “our expectation of operations by U.S. carriersconsistent with NOTAMs does not indicate U.S. government acceptance of China’s requirementsfor operating in the newly declared ECS ADIZ.”73 U.S. officials emphasized their concern for thesafety of commercial aviation in a potentially volatile situation. To some observers, the messages
seemed to be mixed and to undercut the U.S. government’s stated refusal to accept the ECS
ADIZ.74 Other observers saw the State Department position as a diplomatic solution thatsimultaneously upheld the official U.S. protests and the interests of aviation safety. The PRC
MFA expressed “appreciation” to the United States for its “constructive attitude” and“cooperation” but accused Japan, whose airlines do not abide by the Chinese requirements insome circumstances, of “maliciously hyping” the matter and urged Japan to “correct its
mistakes.”75 PRC media used the U.S. statement to claim “cooperation” in “jointly” ensuring
flight safety and to support the legitimacy of the ECS ADIZ.76 The U.S. statement on NOTAMs
appeared amid a tense time and contrasted with the responses of Japan and South Korea, whichwere advising their commercial airlines not to submit flight plans to the PRC in non-compliancewith its ECS ADIZ rules. The ROK later advised its airlines to abide by the PRC’s NOTAM.
In a letter to National Security Advisor Susan Rice, Representative J. Randy Forbes summarized
concerns about the guidance from the State Department and the FAA that urged U.S. commercial
70“George Washington Carrier Strike Group Joins Annualex,” NNS, November 25, 2013; Phil Stewart and David
Alexander, “Defying China, U.S. Aircraft Fly over East China Sea Without Notification,” Reuters, November 26, 2013;“U.S.: 2 Bombers over China’s New Airspace Were on Long-Planned Training,” Stars and Stripes, November 26,
2013.
71“US Seeking ‘Boring’ Military Operations Near China to Avoid Provocation,” Bloomberg News, October 27, 2014.
72
In early 2014, China moved the information on its ECS ADIZ regulations from a NOTAM, which is usually
temporary, into its permanent Aeronautical Information Publication (AIP), which each country provides to guideaviation under its administration.
73
State Department, “China’s Declared ADIZ—Guidance for U.S. Air Carriers,” November 29, 2013.
74
Nanae Kurashige and Yoshihiro Makino, “Japan Baffled by U.S. Telling Airlines to Respect New Chinese Air
Zone,” Asahi Shimbun, December 1, 2014.
75
PRC MFA, news conference, December 2, 2013.
76“Normal International Flights in China’s East China Air Defense Identification Zone Will Not Be Affected inAnway,” Xinhua, November 28, 2013.

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airlines to comply with China’s ECS ADIZ procedures, arguing that these seemed to contradict
the Administration’s own statements. He wrote that “by submitting flight plans to China while
traversing international airspace, U.S. airlines will be acknowledging the validity of China’s
ADIZ at the same time other elements of the U.S. Government are vigorously, and appropriately,
contesting Beijing’s behavior. Furthermore, at a time when Japan is looking to the United States
to be a strong partner, this decision seems to put us at odds with our ally in Tokyo and suggests alack of policy coordination.”77

U.S. Official Statements in Response to the ECS ADIZIn remarks with Japanese Prime Minister Shinzo Abe on December 3, 2013, in Tokyo, Vice
President Biden expressed concern about the increase in tensions and risk of accidents andmiscalculation. The next day in Beijing, Vice President Biden told President Xi that the UnitedStates does not recognize the ECS ADIZ, looks to China to lower tensions, to avoid enforcementthat could lead to crisis, and to establish channels of communication with Japan and otherneighbors, according to accompanying officials.78 He did not call publicly for Beijing to rescind
its ECS ADIZ.
In early December 2013, Defense Secretary Hagel noted efforts towards developing a stronger
U.S.-PRC “military-to-military relationship” and called on China, Japan, and South Korea to stay
“calm and responsible.” At the same briefing, the Chairman of the Joint Chiefs of Staff, General
Martin Dempsey, said that “it wasn't the declaration of the ADIZ that actually was destabilizing,”
but rather the requirement that all aircraft entering the ADIZ report regardless of whether they
were intending to enter into the sovereign airspace of China that was destabilizing.79
Four members of the Senate Foreign Relations Committee wrote to the PRC Ambassador in
Washington that the unilateral declaration of an ECS ADIZ was “provocative” because it extends
over territories “recognized by the United States as under the administrative control of Japan,”overlaps with other ADIZs, and has procedures that are potentially dangerous. They stated thatthe declaration reinforces the perception that China prefers coercion over rule of law and follows
a disturbing trend of China’s increasingly hostile maritime activities.80
After this series of U.S. statements criticizing Chinese behavior, high-level bilateral meetingsproceeded as planned. In January 2014, Assistant Secretary of State for East Asian and PacificAffairs Daniel Russel traveled to Beijing to hold the 5th round of U.S.-China “Consultations on
the Asia-Pacific.” The State Department issued a Joint Statement on the talks that stressed77

J. Randy Forbes, letter to Susan Rice, December 3, 2013.
White House, Remarks to the Press by Vice President Joe Biden and Prime Minister Shinzo Abe of Japan, Tokyo,
December 3, 2013; Background Briefing by Senior Administration Officials on the Vice President’s Trip, Beijing,
December 4, 2013. The New York Times reported the subtle shift on December 3, “But with China unlikely to rescind amove so laden with nationalistic overtones, the vice president’s focus appeared to be less on rolling back the defense
zone than on neutralizing its impact by persuading the Chinese authorities to stop scrambling fighter jets or otherwise
disrupting the busy air corridors between Japan and China.” A journalist on the trip, Steve Clemons, wrote in The
Atlantic that Abe did not ask Biden publicly to call for a rollback of China’s ADIZ because Abe knew that Biden would
not request that of Xi Jinping and did not want to show “any light” between Japan and the United States. The WallStreet Journal’s editorial “East Asian Blurred Lines” on December 5 contended the Obama Administration did notconvey a clear message and that it shifted from calling for China to roll back its ECS ADIZ declaration.
79
Defense Department, Press Briefing by Secretary Hagel and General Dempsey, Pentagon, December 4, 2013.
80
Robert Menendez, Bob Corker, Marco Rubio, and Benjamin Cardin, letter to Cui Tiankai, December 5, 2013.
78

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17China’s Air Defense Identification Zone (ADIZ)“cooperation” and did not mention the ECS ADIZ.81 The next day in Beijing, Deputy Secretary ofState William Burns co-chaired an interim Strategic Security Dialogue (SSD) between diplomaticand defense officials. The State Department said that Burns stressed avoidance of unilateral action
by “all sides” to assert territorial and maritime claims and efforts by China to reduce tensions in
the East and South China Seas.82 When asked in a January 2014 hearing of the House Armed
Services Committee whether China’s actions violate U.S. interests in freedom of navigation, freeflow of commerce, or peaceful settlement of disputes consistent with international law, a senior
U.S. defense official stated that the ECS ADIZ does not challenge U.S. national security.83

Reaction of Japan
The initial reaction of Japanese leaders to the ECS ADIZ announcement was highly critical. Top
officials called on China to rescind its decision to establish the ADIZ, terming it “dangerous” and“one-sided,” and Prime Minister Shinzo Abe declared that it would not have any effect on
Japan.84 Japanese military aircraft transited the Chinese ADIZ as part of planned exercises withina week of Beijing’s initial announcement. When it was reported that Japanese commercial airlines
initially obeyed Chinese requests for identification in the ADIZ, the Japanese government ordered
its airlines to effectively ignore Chinese administration of the ADIZ. Japanese commercial
aircraft do not file flight plans with Chinese authorities nor respond to requests for identification
on routes transiting the ADIZ but not entering Chinese territorial airspace, for example on theroute from Tokyo to Taipei.
Since late November 2013, Japan has taken a series of actions designed to thwart Chinese
administration of the ADIZ while not further escalating the tense situation. Japan submitted a
proposal to the ICAO to examine whether China’s actions threatened the order and safety ofinternational aviation. Japan’s ADIZ overlaps airspace managed by South Korean air traffic
controllers (the Incheon FIR), but the two countries have managed this contradiction for decades
without conflict. The Abe Cabinet in mid-December 2013 approved new defense guidelines thatemphasize the defense of Japan’s southwest islands against incursions from China. The guidelines
state, “China is ... showing its attempts to change the status quo by coercion.”85 Japan’s
parliament, called the Diet, passed a resolution labeling the ECS ADIZ a violation of internationallaw and called for China to withdraw the ECS ADIZ immediately. Foreign Minister Fumio
Kishida, in a major speech before the Diet in January 2014, indicated Tokyo’s intention to gaininternational support for the freedom of flight above the high seas.86

81

State Department, Joint Statement, List of U.S.-China Cooperative Projects, January 22, 2014.
State Department, Press Briefing and “Press Statement on the Visit of Deputy Secretary of State Burns to Beijing,
China,” January 23, 2014. PRC media reported on Burns’ meetings with PLA Deputy Chief of General Staff Wang
Guanzhong and Vice Foreign Minister Zhang Yesui, and also did not mention differences over the ECS ADIZ.
83
House Armed Services Committee, Hearing on the Rebalance to the Asia-Pacific Region, January 28, 2014.
84“Japan, China Trade Barbs over Controversial Air Defense Zone,” Kyodo News Agency, December 25, 2013.
85
New National Defense Program Guidelines for FY2014 and Beyond (Provisional Translation), Cabinet Office ofJapan, December 17, 2013, http://www.kantei.go.jp/foreign/96_abe/documents/2013/__icsFiles/afieldfile/2014/02/03/
NDPG.pdf.
86“Japan Vows to Take Lead in Ensuring Freedom of Flight Above Open Seas,” Kyodo News Agency, January 25,
2014.
82

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While the Abe Administration has made enhancing defense capabilities a top priority, Japan has
not taken concrete steps to adjust its defense posture or activities to account for the ECS ADIZ.
(The Ministry of Defense had already re-deployed 13 E2-C early warning and surveillance
aircraft to Okinawa from northern Japan in late 2012.)87 As in the past, Japanese fighter aircraftcontinue to scramble and intercept foreign military aircraft that do not identify themselves within
the Japanese ADIZ. Reportedly, the United States and Japan agreed to increase theirreconnaissance and surveillance activities in the East China Sea, presumably to monitor Chinese
practices in the new ADIZ.

U.S.-Japan Alliance Relations
The United States and Japan have coordinated at a high level their individual and collective
responses to China’s ADIZ announcement and have reaffirmed the strength of the U.S.-Japan
alliance. American officials expressed appreciation for Japan’s restraint in what could be a
combustible situation and have joined in criticizing China’s actions as destabilizing.88 At a press
conference during his visit to Tokyo in early December 2013, Vice President Biden said, “We, theUnited States, are deeply concerned by the attempt to unilaterally change the status quo in the
East China Sea.... I told the Prime Minister that we will remain steadfast in our alliancecommitments.”89 S.Res. 412, passed by the Senate in July 2014, expresses firm support for Japanand calls on China to refrain from implementing the ECS ADIZ.
In late 2013, however, the two countries took different approaches in some areas, particularly
guidance to commercial aviation regarding the Chinese NOTAM (see section “U.S. Guidance toCommercial Airlines”). The decision by the U.S. government to apply normal FAA guidance tothe new Chinese NOTAMs contributed to latent anxieties in Tokyo about U.S.-Japan unity andthe relative prioritization of China and Japan in U.S. policymaking.90 Many Japanese strongly
praised the training flight of U.S. B-52 bombers through the Chinese ADIZ but were worried
when the United States appeared to accede to China on commercial airline guidance. Some
American analysts argued that the United States lost credibility by not sufficiently supporting
Japan.91 Any action that the United States takes related to the Senkaku/Diaoyu islands is closely
scrutinized in Japan for indications of supporting either Japan or China; signs of ambivalence inWashington cause some Japanese observers to fear abandonment by the United States. However,
U.S. officials may be concerned that full-throated denunciation of China may embolden Japan totake actions that would further destabilize the tense situation in the East China Sea.92

87

Tsuyoshi Takasawa, “ASDF Monitoring Senkakus 24 Hrs a Day; Radar-Equipped Aircraft Deployed in Bid toPrevent Intrusions by Chinese Planes,” Daily Yomiuri, January 28, 2013.
88
Chuck Hagel, “Hagel Issues Statement on East China Sea Air Defense Identification Zone,” U.S. Department of
Defense, November 23, 2013, http://www.defense.gov/news/newsarticle.aspx?id=121223.
89
Remarks to the Press by Vice President Joe Biden and Prime Minister Shinzo Abe of Japan, The Kantei, Tokyo,
Japan, December 3, 2013.
90
Takashi Oshima, “Japan Questions Whether It Can Still Rely on U.S. Alliance,” Asahi Shimbun, February 4, 2014.
91
Charles Krauthammer, “Woe to U.S. allies,” Washington Post, Op-Ed, December 6, 2013; J. Randy Forbes andMichael Auslin, “U.S. Power Loses Altitude in Asia,” Wall Street Journal, Op-Ed, December 11, 2013.
92
Takashi Oshima, “Reality Check: What the Senkakus Issue Entails for Washington,” Asahi Shimbun, February 25,
2014.

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19China’s Air Defense Identification Zone (ADIZ)The U.S.-Japan Mutual Defense Treaty and the Senkaku/Diaoyu Islands
Some Japanese analysts worry that certain U.S. actions abet China’s claim to administer the
Senkaku/Diaoyu Islands and thus weaken the U.S. commitment to fulfill its treaty obligations as
they relate to the disputed islets. Article 5 of the U.S.-Japan Mutual Defense Treaty states, “EachParty recognizes that an armed attack against either Party in the territories under theadministration 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.”
Because the United States does not take a position on the sovereignty of the Senkaku/Diaoyu
Islands, the fact of Japan’s administration is crucial to the U.S. treaty commitment. For more
information, see CRS Report R42761, Senkaku (Diaoyu/Diaoyutai) Islands Dispute: U.S. Treaty
Obligations, by Mark E. Manyin.
For China, it appears that one major reason for creating the ADIZ could have been to bolster its
implicit claim to administer the disputed islets (see section “Focus on Japan”). If the UnitedStates were to take steps that could be construed as implicit recognition of or acquiescence tosome measure of de facto Chinese administration of the Senkaku/Diaoyu Islands, some mightargue that it could potentially nullify or at least weaken the U.S. defense obligation. In its own
attempt to address this perceived gap, Congress inserted in the FY2013 National Defense
Authorization Act (H.R. 4310, P.L. 112-239) a resolution stating, among other items, that “theunilateral action of a third party will not affect the United States’ acknowledgment of theadministration of Japan over the Senkaku Islands.” Obama Administration officials, including
President Obama during an April 2014 visit to Tokyo, have made similar statements.93 Following
the Chinese ADIZ announcement, U.S. officials in the State Department, Defense Department,
and NSC have periodically reaffirmed the U.S. defense commitment to Japan and all territories
under its administration.
The official U.S. stance that it takes no position on sovereignty in the Japan-China territorial
dispute is further complicated by the fact that the U.S. military has used one of the smallest isletsof the Senkaku/Diaoyu as a bombing range. The United States has not used the islet for training
since 1978, but, according to reports, the U.S. military may be entitled to exercise control overthat territory.94

Reaction of South Korea
South Korean leaders initially voiced their strong displeasure with the PRC’s ECS ADIZ
announcement, but their criticism was not as strident as Japan’s. (One news report stated that the
ROK government had been informed of China’s ADIZ announcement several days in advance.)95
93

During an April 2014 joint press conference with Prime Minister Abe, President Obama said, “... historically they[the Senkaku/Diaoyu islets] have been administered by Japan and we do not believe that they should be subject tochange unilaterally.” During Obama’s visit to Tokyo, the two sides issued a joint statement saying, among other items,“... the United States opposes any unilateral action that seeks to undermine Japan’s administration of the Senkaku
Islands.” The White House Press Office, “Remarks by President Obama and Prime Minister Abe of Japan in Joint Press
Conference,” April 24, 2014, Tokyo, Japan; “U.S.-Japan Joint Statement. The United States and Japan: Shaping the
Future of the Asia-Pacific and Beyond,” April 25, 2014.
94
Takashi Oshima, “Reality Check: What the Senkakus Issue Entails for Washington,” Asahi Shimbun, February 25,
2014.
95
Kim Ji-hyun, “China Informed Seoul of Air Defense Zone,” Korea Herald, November 25, 2013.

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20China’s Air Defense Identification Zone (ADIZ)South Korean Foreign Minister Yun Byung-se said on November 27, 2013, “The issue of the air
defense identification zone is making the already difficult regional situations even more difficult
to deal with.... We see competition and conflict in the region deepening.” In a bilateral meeting ofsenior defense officials on November 28, South Korea reportedly asked China to redraw its ADIZ
so that it did not overlap with the Korean ADIZ, but the Chinese officials rejected this request.96
On December 8, South Korea announced that it would expand its own ADIZ to include area
overlapping with the Japanese and Chinese ADIZs, though conforming to the South Korean FIR.
The ROK military expressed its intent to increase patrols in the ADIZ and on December 9 flew apatrol aircraft through the zone without notifying China.97
The decision by South Korea to expand its ADIZ to include airspace overlapping with Chineseand Japanese ADIZs showed elements of both consideration and parochialism. On the one hand,
the South Korean ADIZ respects the freedom of overflight, including foreign state aircraft. Seoul
also consulted with the United States, China, and Japan before making its announcement on
December 8, 2013. The calm reactions of Chinese and Japanese officials to the expanded ADIZ
likely reflected this consideration. On the other hand, the response in kind to China could appear
to legitimize some of Beijing’s claims about a need to safeguard national interests through anenlarged ADIZ. South Korea’s pursuit of its national interest may have undercut attempts by theUnited States and Japan to de-escalate the situation based on mutually acceptable principles.
Furthermore, the new overlapping area could increase the risk of an incident.
The establishment of the PRC’s ECS ADIZ came at a time when South Korea was building closer
ties to China and ROK-Japan relations remained mired in acrimonious historical issues regarding
Imperial Japan’s actions in the early 20th century. The ECS ADIZ episode appears to have cooled
the China-South Korea relationship temporarily by casting a negative light on China’s strategy
and intentions, although China-ROK relations improved noticeably in 2014. Washington andSeoul are attempting to maintain a strong bilateral relationship while navigating aroundsensitivities with neighboring countries. One American scholar (and former White House official)argued that the apparent willingness of Seoul to seek a separate accommodation with Beijing,
while ignoring the concerns of Tokyo and Washington, was short-sighted and raised questions
about South Korea’s strategic alignment.98
The ADIZ incident also rekindled the long-simmering dispute between China and South Korea
over a submerged rock in the Yellow Sea. The undersea feature, called Socotra Rock by theUnited States, Ieodo by South Korea, and Suyan Rock by China, is located in the area of the sea
claimed by both China and South Korea as within their EEZs. Since 2003, South Korea has
maintained an ocean research station built on a raised platform above the submerged rock. The
new Chinese ADIZ includes airspace over Socotra Rock, which had previously been within theJapanese but not the Korean ADIZ, although it is now included within the expanded Korean
ADIZ.

96

“Korea Calls for Re-drawing of Air Zone, China Rejects,” Arirang News, transcript of television news report,
November 30, 2013, http://www.arirang.co.kr/News/News_View.asp?nseq=153704.
97“East Asia—Strong Opposition to PRC ADIZ, ROK Announces ADIZ Expansion,” Open Source Center, Report,
December 10, 2013.
98
Victor Cha, “Korea’s Mistake on China’s ADIZ Controversy,” Center for Strategic and International Studies, Korea
Chair Platform, December 2, 2013.

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Reaction of Taiwan
On November 23, 2013, the Taiwan government declared that (1) Taiwan has sovereignty overthe Diaoyutai (Senkaku) Islands with no change due to the PRC’s ECS ADIZ and that Taiwan
will continue to defend that sovereignty over the islands and continue operations to protect
fishermen; (2) each side should use peaceful dialogue to resolve disputes in line with President
Ma Ying-jeou’s “East China Sea Peace Initiative” of August 2012; (3) Taiwan’s military will use
peaceful principles of Ma’s initiative and adopt appropriate measures in light of the overlap
between the PRC and Taiwan ADIZs; and (4) Taiwan is “gravely concerned” and will maintainclose contact with all sides to maintain peace and stability.99 In contrast to Japan, Taiwan
instructed its commercial airlines to submit flight plans to the PRC’s authorities, arguing that thegeneral directive is in accordance with international regulations rather than in recognition of the
PRC’s ECS ADIZ.100 The Democratic Progressive Party (DPP), an opposition party more wary of
the PRC than the ruling Nationalist Party (also known as the Kuomintang), urged a stronger
protest. Taiwan’s legislators from both parties issued a joint statement from the Legislative Yuan
urging the Ma Administration to lodge a strong protest, commercial airlines not to submit flightplans to the PRC, and the PRC to rescind its ECS ADIZ. In 2010, Taiwan protested strongly to
Japan when it expanded slightly its ADIZ to fully cover the airspace over Japan’s Yonaguni
Island, though there is no dispute over the island. Taiwan opposed the change to Japan’s ADIZ
line, and Taiwan’s Foreign Minister raised a question about whether Japan’s redrawn ADIZ would“threaten” Taiwan’s airspace.101
After the lawmakers’ joint statement, Taiwan’s Executive Yuan, or Cabinet, added that the
military would not change its operations as a result of the PRC’s ECS ADIZ announcement andwould conduct patrols and reconnaissance operations in Taiwan’s ADIZ.102 Although Taiwan
demarcates its ADIZ as extending west of the Taiwan Strait to cover part of the mainland,103
Taiwan’s Air Force and the PLA Air Force have a tacit understanding that their fighters should notcross the median line in the Taiwan Strait (Taiwan does not attempt to administer the portion of
the ADIZ over mainland China). Taiwan’s Air Force patrols and training continued unchanged,
including up to 30 patrols in the overlap between their ADIZs in the week after the PRC’s
announcement.104 Taiwan has protested and scrambled fighters in response to the flights of the
PLA’s aircraft through Taiwan’s ADIZ, including aircraft not flying toward Taiwan. For example,
Taiwan’s military announced that on August 25, 2014, a PLA Y-8 surveillance aircraft flew fourtimes through the southwestern corner of Taiwan’s ADIZ. Taiwan’s Air Force scrambled fighters
to intercept the Y-8 aircraft and “escort” it out of the ADIZ, though the PRC planes did not fly
toward Taiwan.105

99“Executive Yuan Responds Firmly to Mainland China’s East China Sea ADIZ Declaration,” Office of Information
Services, Executive Yuan, November 29, 2013.
100“Taiwan Conveys Position on China’s ADIZ to U.S.,” Central News Agency, Taipei, November 27, 2013.
101
CRS interviews in Taipei; Shih Hsiu-chuan, “Japan Extends ADIZ into Taiwan Space,” Taipei Times, June 26,
2010.
102
Central News Agency, Taipei, November 29, 2013.
103
The United States does not recognize Taiwan’s demarcated ADIZ, partly because it extends over mainland China.
104
Central News Agency, Taipei, December 2, 2013, citing a Lieutenant General of the Air Force and the Defense
Minister.
105“Chinese Aircraft Intercepted in Taiwan’s Air Defense Zone,” Central News Agency, August 26, 2014

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Implications for U.S. Policy
The PRC’s ECS ADIZ has implications for U.S. policy in terms of the potential for conflict,
escalation of tension, Sino-Japanese tensions, a strategic challenge to the United States, and U.S.China military-to-military exchanges.

Potential for Conflict
By creating an overlapping area where different militaries seek to administer airspace, China’s
ECS ADIZ may increase the risk of an incident that could lead to a military conflict.106 A
confrontation between military aircraft at close proximity could provoke the use of force and thenretaliation, especially in the absence of mutual trust. Depending on the effectiveness of deescalation measures and the intent of the parties involved, a small-scale clash could escalate to amore significant conflict between large, modern militaries. In early 2013, PLA Major General
Zhang Zhaozhong said that Beijing needs to “break” Tokyo’s ADIZ, saying, “If their fighterscome and our fighters don't go out, from a diplomatic and military perspective, there is noreciprocity: It’s not good. But if both sides bring out fighter jets, as to whether that might lead to aclash between them, that is another question.”107
The incidents in May and June 2014 between Chinese and Japanese aircraft (see section “ChinaJapan Incidents in Mid-2014”) illustrate the potential for a spark to ignite a larger, combustible
situation. The potential for an accidental clash in the air provided a reminder of the aircraft
collision crisis of 2001, when a PLA Navy F-8 fighter hit a U.S. Navy EP-3 reconnaissance planeflying over the South China Sea. The crisis took place in spite of U.S. protests to the PRC months
before the crisis that PLA pilots engaged in a pattern of increasingly unsafe behavior.108
The presence of unmanned aerial vehicles (UAVs) in the airspace over the disputed islets could
also spark conflict. On September 9, 2013, the PLA apparently flew a UAV within 125 miles of
the Senkaku Islands, without entering Japan’s territorial airspace. Japan scrambled fighters in
response to the unidentified UAV that Japan said intruded into its ADIZ. Later, in October, Japan
reportedly prepared an option to shoot down foreign UAVs that do not respond to warnings toleave Japanese territorial airspace.109 The PRC Defense Ministry said then that the PLA’s UAVs
are used in normal training and activities and that Japan’s shooting down of aircraft would be an
act of war.110
The PRC official media’s justifications for the ECS ADIZ included arguments about China’s rightto “self-defense” and to safeguard “sovereignty,” but not signals of deterrence to prevent a crisis
or war. In the past, the PRC has warned of the use of force or retaliation to compel an adversary
106

Carlyle Thayer, “China’s Air Defense Identification Zone – 1,” Background Brief, Thayer Consultancy, November
25, 2013.
107
Yuka Hayashi, Jeremy Page, and Julian Barnes, “Tensions Flare As Japan Says China Threatened Its Forces,” WallStreet Journal, February 6, 2013.
108
CRS Report RL30946, China-U.S. Aircraft Collision Incident of April 2001: Assessments and Policy Implications,by Shirley A. Kan et al.
109“Japan to shoot down foreign drones that invade its airspace,” Kyodo News Agency, October 20, 2013.
110
Wang Jingguo “Defense Ministry Spokesman Replies to Reporter’s Question on Issue Involving Japan,” Xinhua,
October 26, 2013.

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to back down from an impending crisis or conflict.111 For example, in threats against Taiwan in
December 1992 and March 1993, CPC General Secretary Jiang Zemin and Premier Li Pengwarned of necessary “resolute” or “drastic” measures to prevent Taiwan’s independence. Past
PRC warnings have included phrases such as “we will not attack if we are not attacked; but if weare attacked, we will certainly counter-attack.” Considering this pattern, the PRC’s ECS ADIZ
does not appear intended to provoke a conflict with Japan, South Korea, Taiwan, or the UnitedStates. The action is consistent with an assessment in 2013 by several experts that found that themost likely challenge to the U.S.-Japan alliance over the next 15 to 20 years is not a full-scale
military conflict between China and Japan or the United States but the more likely attempts by
China to use coercively its growing military capabilities to influence or resolve disputes withJapan in China’s favor without resorting to an attack.112

Escalation of Tension
To U.S. Naval War College scholar Andrew Erickson and other experts on the PLA, the creationof the ECS ADIZ fits a pattern of numerous actions by China that intentionally raise the risks ofaccidental clashes and exacerbate tensions to seek concessions from other countries or acceptanceof a new status quo.113 These actions also put pressure on the U.S.-Japan alliance. Erickson andothers assert that Beijing perceives that it can control the escalation of tension while shaping
foreign security perceptions and seeking compromises. A chief justice in the court system of the
PLA Navy stated that the ECS ADIZ “will not only not bring about an intensification of thesituation in the East China Sea, it will actually control the escalation of the complex situation in
the East China Sea and be an effective measure for protecting the peace and stability of the East
China Sea.”114 This quote illustrates the point that, in the eyes of many Chinese strategists, someactions that escalate tensions may not be inherently dangerous or undesirable, and thus othercountries should not be outraged by these tactics.115
Since September 2012, the PRC’s actions have shown a trend toward greater use of military
assets to assert administrative control in the East China Sea, on top of the previously high-profile
use of official maritime law enforcement ships.116 The PRC’s militarized actions have escalated
from regular patrols by official maritime law enforcement ships (including into the territorial
waters of the Senkaku/Diaoyu Islands to claim them as the PRC’s territorial waters), patrols by
PLA Navy ships, patrols by official aircraft, announced scrambling of fighters to match Japan’s
scrambling of fighters, to PLA Navy actions beyond patrols,117 and establishment of the ECS
111
Paul Godwin and Alice Miller, “China’s Forbearance Has Limits: Chinese Threat and Retaliation Signaling and Its
Implications for a Sino-American Military Confrontation,” Center for the Study of Chinese Military Affairs, Institutefor National Strategic Studies, National Defense University, Washington, DC, April 2013.
112
Michael Swaine, Mike Mochizuki, Michael Brown, Paul Giarra, Douglas Paal, Rachel Odell, Raymond Lu, Oliver
Palmer, and Xu Ren, China’s Military and the U.S.-Japan Alliance in 2030 (Washington: Carnegie Endowment, 2013).
113
Andrew Erickson, “Watch This Space: China’s New Air Defense Zone,” China Real Time blog, Wall Street
Journal, November 25, 2013; Ian Easton, “China’s Evolving Reconnaissance-Strike Capabilities,” Project 2049
Institute, February 2014.
114“China’s Demarcation of the East China Sea Air Defense Identification Zone is Reasonable and Legal,” Liberation
Army Daily, November 25, 2013.
115“NIDS China Security Report 2013,” National Institute of Defense Studies, Japan, January 2014.
116
The trends are based on Shirley Kan’s record of the PRC’s actions in maritime and territorial disputes.
117
A PLA Navy frigate reportedly directed its fire-control radar at a Japanese Maritime Self-Defense Force (MSDF)
helicopter, and another PLA Navy frigate directed its fire-control radar at an MSDF destroyer. Beijing has denied that
PLA Navy vessels directed their fire-control radar at Japanese military craft.

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24China’s Air Defense Identification Zone (ADIZ)ADIZ for PLA air control. Beijing has justified these other actions by its need to defend China
from increasing external threats.
The PRC’s designation of the ECS ADIZ further raised the prospects that East China Sea tensions
could escalate into a crisis involving Japan, a U.S. ally, and that the United States could be drawn
into a conflict with the PRC. It is unclear whether the PRC was interested in raising tension,
perhaps to provoke Japan, to undercut U.S. alliances by trying to undermine trust in U.S.
commitment or capability, or to hint of U.S.-China co-management of what Beijing calls “third
parties” such as U.S. allies and partners.118 The concept of a “G-2,” or Group of Two, between the
United States and China continues to worry some countries wary of China.119
In late 2013, the PRC blamed Japan alone for “provocations” and the lack of dialogue to manage
or reduce tension. In March 2014, the PRC MFA did not agree to a Japanese proposal for amaritime liaison mechanism to avoid escalation of tension, saying instead that the problem
remained with what the PRC called Japan’s unilateral provocations. China eventually agreed in
September to resume talks with Japan on the communication mechanism, which would establish ahotline between defense officials and determine radio frequencies to be used for communications
between ships and aircraft of the two nations.120 The face-to-face meeting of Prime Minister Abe
and President Xi in November 2014 may provide momentum to those talks.

Focus on JapanThe designation of the ECS ADIZ appeared to focus on the PRC’s goals vis-à-vis Japan inparticular, although PRC officials cited broad foreign precedents for ADIZs and stated that the
ECS ADIZ is not aimed at any country. Chinese commentators drew attention to Japan’s ADIZ
before and after the PRC’s formal announcement of its ECS ADIZ.121 The PLA’s newspaper
published an article that criticized Japan for its concerns about the ECS ADIZ and for theJapanese government’s purchase of three of the disputed islets, saying that the PRC’s demarcationof the ECS ADIZ “of course had to include the Diaoyu Islands.”122 Official PRC media publishedan article arguing that the ECS ADIZ announcement has started the struggle with Japan over air
control over the East China Sea.123 After the ECS ADIZ announcement, commentary in theofficial PRC media harshly criticized only Japan for its reaction, while expressing “appreciation”
to the United States for its “neutral stance” on the China-Japan territorial dispute.124 Althoughother neighbors protested, Chinese media have avoided criticisms of Seoul or Taipei.

118

For example, a PRC article referred a vision of a “new type” of U.S.-China military relationship that included anelement of preventing “third party factors from kidnapping” that relationship (“Summary of the ‘Building a New Typeof Great Power Relationship’ Academic Symposium,” Guoji Zhanwang, Shanghai Institute of International Studies,
July 15, 2013).
119
James Jay Carafano, “Why a U.S.-China ‘G-2’ Won’t Work,” National Interest, January 6, 2014.
120“Japan, China head back to table over maritime hotline,” Yomiuri Shimbun, September 27, 2014.
121
Luo Yuan, China Council for the Promotion of Strategic Culture, “Military expert: Rules should be set up for Japanin East China Sea,” Liberation Army Daily and China Military Online, February 18, 2013.
122“Words of Worry Come from Having an Ambitious Heart,” Liberation Army Daily, November 26, 2013.
123
Air Control over East China Sea, China or Japan, Who Has the Edge?” Cankao Xiaoxi, December 12, 2013.
124“China’s Setup of Air Zone Legitimate, Conducive to Regional Peace,” Xinhua, November 24, 2013.

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In one view, the PRC’s objective might be primarily directed at rival claims with Japan over the
Senkaku/Diaoyu/Diaoyutai Islands.125 The ECS ADIZ might be a means to press Japan torecognize the existence of a dispute and enter into negotiations. A retired PLA general, Xu
Guangyu, said that “the eventual purpose [of the ECS ADIZ] is to force Japan to sit down with
China, to avoid miscalculation and escalation.”126 The PRC could claim its own or joint
management to undermine Japan’s exclusive administration of the islands, which some mightargue could undercut the applicability of the U.S.-Japan defense treaty (see section “The U.S.Japan Mutual Defense Treaty and the Senkaku/Diaoyu Isl”). The ECS ADIZ could be viewed as
one action among many that the PRC has taken to try to change the status quo at the expense ofrival claimants in the East and South China Sea.127
China announced the ECS ADIZ against the backdrop of numerous official statements that go
beyond the two countries’ territorial dispute and that appear intended to discredit Japan more
broadly. The ECS ADIZ announcement came shortly before the PRC’s high-profile
commemoration of the 70th anniversary of the Cairo Declaration, an event at which the PRC not
only reiterated its claim to sovereignty over the disputed islands but also continued a campaign ofcriticizing Japan’s historical aggression in World War II as well as Japan’s behavior today.128 If
the PRC’s challenge to Japan indeed extends beyond a disagreement over disputed islands, thenconcessions by Japan would not necessarily reduce the risk of conflict and could encourage
additional coercive actions by the PRC. China could be engaging in zero-sum competition withJapan that entails broad economic, military, and political rivalry on the world stage—a rivalry inwhich the Senkaku-Diaoyu Islands dispute is only one element. Another perspective is that theappearance of China-Japan competition is the product of China’s emergence as a major power.

Strategic Challenge to U.S. Leadership and Alliances
There is debate in the academic and policy communities over whether the PRC accepts thecurrent international order or is seeking to re-define it. The creation of the ECS ADIZ suggests tosome observers that the PRC is asserting its own rules rather than accepting established rules andpractice. Beijing has rebutted the charges that it is upending the international order and hasargued that other countries have indicated their agreement with the ECS ADIZ by complying with
PRC regulations. The PRC MND claimed that, in the first month after announcing the ECS
ADIZ, the PLA “controlled” almost 800 flights of foreign military aircraft that entered the ECS
ADIZ, and 56 airlines from 23 “countries and regions” notified PRC civil aviation authorities of
their flight plans for 21,475 flights.129 At the same time, Beijing also has questioned one feature125

For example: Douglas Paal, “Contradictions in China’s Foreign Policy,” Carnegie Endowment, December 13, 2013.
Zhang Hong and Minnie Chan, “Beijing’s Air Defense Zone Aimed At Making Tokyo Negotiate, Analysts Say,”
South China Morning Post, Hong Kong, December 1, 2013.
127
After the PRC took control of Scarborough Shoal at the Philippines’ expense in 2012, articles in PRC media havediscussed whether to use the “Scarborough Model” for other claims, including the Senkaku/Diaoyu Islands. China
News Agency, May 12, 2012; China Economic Weekly, August 27, 2012; International Herald Leader, April 12, 2013.
128
U.S. President Franklin Roosevelt, U.K. Prime Minister Winston Churchill, and Republic of China President ChiangKai-shek issued the “Cairo Declaration” during World War II on December 1, 1943. The declaration addressed
territories controlled by Japan. The PRC has used the Cairo Declaration to argue that Japan should restore theSenkaku/Diaoyu islands to China because Japan “stole” those islands in 1895. On December 2, the PLA’s Liberation
Army Daily published an article to argue that “the Cairo Declaration provided an ample de jure basis for China toprotect its right over the Diaoyu Islands.”
129
PRC MND, news conference, December 26, 2013. “Regions” could be a reference to Taiwan, Hong Kong, andMacau.
126

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China’s Air Defense Identification Zone (ADIZ)of the international order: U.S. military alliances. Right after the ECS ADIZ announcement, Vice
Foreign Minister Liu Zhenmin said that “in Asia, military alliances are still an objective
existence. Some external powers and regional members show their support. But for China, it isalready an outdated concept in international relations, and does not fit with the new type of stateto-state relations.”130
A related question is whether the PRC is reacting to the actions of other countries or is taking
proactive steps to incrementally advance its maritime claims and project power at the expense ofother countries. The Director of National Intelligence (DNI) James Clapper testified to Congressin January 2014 that “China will probably continue its increasingly proactive approach tomaritime disputes, including a hardline stance toward Japan over the Senkaku Islands.” DNIClapper also stated that the PRC has endeavored indirectly to counterbalance U.S. influence andto sow doubts about the sustainability of the U.S. strategic rebalance to Asia and U.S. willingness
to support its allies and partners.131
Some analysts assess that the PRC’s ECS ADIZ is changing international rules and testing (if notcosting) the United States its international influence.132 Michael Green, a former Senior Director
for Asia at the NSC during the George W. Bush Administration, asks whether the Obama
Administration sees the ECS ADIZ as “a Japan-China problem that needs to be managed or as
part of a longer-term test of wills with Beijing.” Green also argues that the ECS ADIZ
announcement was not “just an ill-conceived slap by Beijing against a testy Japan. The reality isthat the new ECS ADIZ is part of a longer-term attempt by Beijing to chip away at the regional
status quo and assert greater control over the East and South China Seas.” He urged theAdministration to consider China’s actions as the use of coercion to change the status quo.133
Another commentator saw a strategic challenge:
Over the past five to 10 years, China’s “peaceful rise” has given way to more assertive
efforts to challenge the regional status quo. There has been no formal declaration of a
Chinese “Monroe Doctrine,” no announcement of a Beijing-centered “Asian Co-Prosperity
Sphere,” and certainly no fiery speeches denouncing the existing order the way that Hitler
used to rail against Versailles. Instead, what we’ve seen is a more gradual, low-intensity
effort to challenge current arrangements and to pressure other states to accept revisions thatare more to Beijing’s liking. Sometimes, the object of attention is a reef or some small
islands; sometimes it is a declaration of sovereignty over contested waters; and mostrecently, it was the unilateral announcement of an “air defense identification zone.” In eachcase, the goal has been to reinforce Chinese claims to particular territorial arrangements, butalso to establish China’s position as the power in the region whose demands must be
respected.134

130“Military Alliances No Longer Relevant: Diplomat,” Xinhua, December 3, 2013.
Senate Select Committee on Intelligence, Hearing on the “Worldwide Threat Assessment,” January 29, 2014.
132
For example, Michael Auslin, “The Day America Lost Asia,” Politico, November 26, 2013; Ian Bremmer, “China’s
Air Zone Announcement Was Just the Beginning,” Reuters, December 9, 2013; Philip Stephens, “Beijing Has Turned
Control of the Air Space Around the Senkaku Islands Into a Test of the U.S.,” Financial Times, December 10, 2013.
133
Mark Landler, “Airspace Claim Forces Obama to Flesh Out China Strategy,” New York Times, November 27, 2013;
Michael Green, “Safeguarding the Seas,” Foreign Affairs, December 2, 2013.
134
Stephen Walt, “How Long Will China Tolerate America’s Role in Asia?” Foreign Policy, December 2, 2013.
131

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Former Assistant Secretary of State for East Asian and Pacific Affairs Kurt Campbell observedthat the PRC’s military warning to civilian airliners “creates unwelcome comparisons between theformer Soviet Union with today’s China.... It suggests a nation more interested in the pursuit of
19th century-like spheres of influence and prohibited areas, rather than a 21st-century nationcommitted to sustaining an open and transparent regional operating system.”135
A China specialist at the Naval War College, Peter Dutton, assessed that the PRC is challenging
the U.S.-led, open maritime system and is using force and legal assertions: a “power and law
approach.” He argued that the ECS ADIZ is consistent with a strategy to use legal language toincrease incrementally China’s jurisdictional control over the “near seas.” Dutton argued that the
ECS ADIZ has a legal implication regarding accession of the United States to UNCLOS andleadership of international rules. Another China expert, Bonnie Glaser, testified that the PRC’s
use of coercion, bullying, and “salami-slicing” tactics, including the ECS ADIZ, has implications
for U.S.-PRC strategic competition for power.136
In another view, the issue is the extent of the strategic challenge. Observers holding this view
believe that China’s challenge could be limited to Asia, or what the PRC calls its “periphery.” In
this view, Beijing is not broadly overturning the international order but subtly and selectively
challenging access to the global commons. A professor at Naval War College wrote that the
PRC’s strategy is not access denial but “selective access denial.” He noted that “should Beijing
try to bar foreign access to Asian seas and skies entirely, it would simplify the problem for
Washington. No U.S. president could tolerate blanket access denial.... Instead, though, China isdaring America to mount a massive effort to defend things of seemingly trivial importance.”137

Military-to-Military Exchanges
The PRC’s formal announcement of the ECS ADIZ showed continued limitations in U.S. militarycontacts with the PLA. The PLA did not present a particular plan or detailed discussion of a new
ADIZ during a meeting in August 2013 in Honolulu of the bilateral Military Maritime
Consultative Agreement (MMCA) between PACOM and the PLA Navy. The PLA Air Force did
not attend the MMCA meeting. The ECS ADIZ announcement appeared right after the Vice Chiefof Naval Operations (CNO), Admiral Mark Ferguson, visited the PRC on November 10-14, 2013.
He met with PLA Navy officials who included Commander Wu Shengli and Vice Admiral Su
Zhiqian, the East Sea Fleet’s Commander, but was not informed of the PRC’s plan to establish an
ADIZ.138 Defense Secretary Hagel acknowledged in a joint press conference with Chairman of
the Joint Chiefs of Staff Martin Dempsey on December 4, 2013, that he had “not spoken to my
Chinese counterpart” about the ADIZ; General Dempsey indicated that he had “actually reached
out to the schedulers to connect me with my Chinese counterpart,” but that contact had not yet

135

Kurt Campbell, “China is Treading on Thin Ice in the Pacific,” Financial Times, December 2, 2013.
Peter Dutton, testimony; and Bonnie Glaser, Center for Strategic and International Studies (CSIS), testimony at a
Hearing of the House Armed Services Subcommittee on Seapower and Projection Forces and House Foreign Affairs
Subcommittee on Asia and the Pacific, “Maritime Sovereignty in the East and South China Seas,” January 14, 2014.
Glaser defined “salami-slicing” as the PRC’s use of small steps, none of which by itself is a casus belli, to graduallychange the status quo in its favor.
137
James Holmes, “China’s Selective Access-Denial Strategy,” National Interest, December 3, 2013.
138
Bonnie Glaser and Jacqueline Vitello, “US-China Relations: Biden Visits China amid ADIZ Fracas,” Comparative
Connections (Vol. 13 No 3.), Center for Strategic and International Studies, January 15, 2014.
136

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been made.139 Hagel noted efforts towards developing a “stronger military-to-military”
relationship with the PLA. Some officials and observers opined that military-to-military
management of tensions can reduce the risks to stability from the increasingly competitive
aspects of the PRC’s approach to the United States and U.S. allies. For more information, see
CRS Report RL32496, U.S.-China Military Contacts: Issues for Congress, by Shirley A. Kan.

Potential Further PRC Actions
The PRC has a wide array of options related to the ECS ADIZ. Actions likely to be seen as
constructive by other countries include restrained enforcement of the ECS ADIZ rules; preventionof nationalist activists from landing on the disputed islands; and consultations with othercountries and the ICAO to conform its ECS ADIZ to international rules and practice. However, in
an indication that the ECS ADIZ poses a challenge beyond the island dispute with Japan, Beijing
stated that it was considering other ADIZs. On the day of the ECS ADIZ announcement, the
MND stated that the PRC will establish other ADIZs “at the right moment after necessary
preparations are completed.”140 The MND spokesperson reiterated that position at a news
conference on November 28, 2013.
As possible future steps, China could announce an ADIZ for the South China Sea, an ADIZ for
the Tonkin Gulf, and/or an ADIZ for the Yellow Sea. Although the MND spokesman assured that
the ECS ADIZ is beyond national airspace and not a “no-fly zone,” the PLA in the past has tried
to assert that it may deny access to the Yellow Sea for foreign military exercises or transit.141 The
PRC also could declare an ADIZ for the Taiwan Strait or extend the ECS ADIZ toward Taiwan.
These possible future steps raise questions about the need for international talks with Beijing andabout U.S. strategy for discouraging China from announcing new, problematic ADIZs (seesection “Oppose Other PRC ADIZs” for U.S. official statements) and for responding to potential
new ADIZs.
In the near term, the PRC would face significant challenges in implementing an ADIZ over theSouth China Sea. The PLA may need to build up its radar and other capabilities to support
another ADIZ, especially to cover the southern part of the South China Sea, which is a great
distance from PLA bases. The PLA Air Force has limited ability to project power farther from
PRC territory, including over the South China Sea, although these limitations will depend on the
PLA’s aerial refueling capability.142 The PRC occupies the Paracel Islands as well as seven reefs,
but no islands, in the Spratly Islands. However, since 2013 Chinese ships have been dredging theseabed around several reefs to construct artificial islands that could support airfields, adevelopment that may alleviate the PLA’s need for in-flight refueling to maintain air control of139“Department of Defense Press Briefing by Secretary Hagel and General Dempsey in the Pentagon Briefing Room,”
U.S. Department of Defense, December 4, 2013, http://www.defense.gov/transcripts/transcript.aspx?transcriptid=5335.
140
PRC MND, “Response to Questions on the Establishment of the ECS ADIZ,” November 23, 2013.
141
For example, on July 20, 2010, the United States and ROK announced combined military exercises in the seas to thewest and east of the ROK, commonly called the Yellow Sea and Sea of Japan, in response to the North Korean attackon the ROK naval ship Cheonan on March 26 that killed 46 sailors. However, even before the announcement and eventhough the exercises were not aimed at the PRC, PLA General Ma Xiaotian expressed “opposition” to the expected
U.S.-ROK exercises in the Yellow Sea. After the PLA’s statement, the PRC MFA revised its language from “concern”
to “opposition” to any foreign military ships and aircraft entering or flying over the Yellow Sea.
142
David Shlapak, “Equipping the PLAAF: The Long March to Modernity,” The Chinese Air Force, National Defense
University, Institute for National Strategic Studies, Center for the Study of Chinese Military Affairs, 2012.

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the South China Sea.143 Official PRC media indicated that an aircraft carrier could help with the
problem of limited endurance of fighters flying patrols over the South China Sea, especially out
to the southern edge of China’s claimed jurisdiction.144 In December 2013, the PLA Navy’s firstaircraft carrier, the Liaoning, sailed to the South China Sea for testing and training. At acongressional hearing in February 2014, the Director of the Defense Intelligence Agency
Lieutenant General Michael Flynn testified that China’s first aircraft carrier, commissioned in late2012, will not reach its full potential until it acquires an operational fixedǦwing air regiment overthe next several years.145
Announcing an ADIZ for the South China Sea could create political problems for the PRC. Sucha move could exacerbate tense ties with some countries and could spur a more coordinatedapproach at the 10-nation Association of Southeast Asian Nations (ASEAN), which, in turn, could
compel Beijing to deal multilaterally with several Southeast Asian countries instead of Beijing’s
preferred use of leverage in bilateral contacts. Indeed, PRC media indicated that a “South China
Sea ADIZ” would present complicated problems for the PRC’s external engagement with
Southeast Asian countries, drive a wedge between China and ASEAN, and raise concern about a“China threat.” In early 2014, the PRC MFA denied that China was preparing to announce a“South China Sea ADIZ” by saying that China does not feel a threat from Southeast Asian
countries and that reports of such an ADIZ were rumors created by Japan.146 In November 2014, a
PRC MND spokesperson addressed the possibility of a South China Sea ADIZ, “We have said on
many occasions that whether or not to set up an [ADIZ] depends upon various factors, forexample, the air threat that the country faces and the overall security environment. And we haveconfidence as to our relationship with the countries surrounding the South China Sea and we also
have confidence in the overall stability of the situation in the area.”147
Following the establishment of the ECS ADIZ, China could challenge operationally Japan’s
administrative control of the Senkaku/Diaoyu islands. For example, the PLA could fly aircraft,including helicopters or fixed-wing aircraft, into the airspace over disputed islands or reefs, or
PLA aircraft could intercept foreign aircraft. Official PRC agencies or the PLA could land UAVs
on a disputed island. China Coast Guard or PLA Navy ships could enter the territorial waters of
the Senkaku Islands for longer periods of time. The PRC could then portray the reactions of Japan(and/or other countries) as “provocations” and exploit them to advance the PRC’s control.

Costs and Consequences for the PRC
The PRC’s management of the ECS ADIZ and its decision whether or not to establish other
ADIZs will be based on Beijing’s perception of costs and benefits. Some observers assess that the
PRC incurred costs by, in one stroke, tainting the international image of its “peaceful rise” andundercutting multiple engagements with Japan, South Korea, Taiwan, Australia, the United
143
James Hardy, Krispen Atkinson, Richard Hurley, and Michael Cohen, “China goes all out with major islandbuilding project in Spratlys,” IHS Jane’s Defence Weekly, June 20 ,2014.
144“Aircraft Carrier Liaoning Battle Group Has Arrived in the South China Sea,” China Youth Daily, December 6,
2013.
145
Senate Armed Services Committee, hearing on Annual Threat Assessment, February 11, 2014.
146
Wu Shicun, Director of the National Institute for South China Sea Studies, “Ignore Noise Around South China Sea
ADIZ,” Global Times, January 14, 2014; Xinhua, February 1, 2014.
147
PRC MND regular press conference on November 27, 2014.

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States, and other countries.148 Defense Secretary Hagel and Singapore’s Minister of Defense Ng
Eng Hen met on December 12, 2013, and they discussed China’s “troubling” ECS ADIZ
announcement and the concerns of Southeast Asian nations.149 Days later, the leaders of Japanand ASEAN held a summit in Tokyo. They agreed to enhance cooperation in ensuring thefreedom of overflight and civil aviation safety in accordance with universally recognizedprinciples of international law, including the 1982 UNCLOS, and standards of the ICAO, without
explicitly pointing to the PRC’s ECS ADIZ announcement.150 PRC official media, nonetheless,insisted that Southeast Asian leaders had shown prudence and a commendable unwillingness totake a clear position on whether to align with Japan to counter China on the issue of freedom ofnavigation.151
Some commentaries called for a strong, sustained U.S. stance to oppose China’s ECS ADIZ, toforestall future challenges, as well as to bolster U.S. leadership in a coordinated approach among
allies and partners. The Washington Post called for opposition, arguing that “if this air zone isallowed to stand, it may encourage China to step up the pressure in other ways, too.”152 The New
York Times contended that “given China’s unilateral decision, with its threat of possible military
action, the United States needed to stand up for its ally Japan, for the principle of freedom ofnavigation of the seas and skies, and for other Asian nations that also have territorial disputes
with China in the East China Sea and the South China Sea.”153
Observers noted that the PRC’s ECS ADIZ declaration raises a question of whether and how to
impose costs, including cancellations of symbolic visits.154 Some officials say that dialogue iscritical in times of tension and that it is more important to reduce the rising risks in therelationship with Beijing. Other analysts worry about the possibility of sending unwanted signals
to Beijing if the United States or other countries accept the PRC’s provocations without penalty.
Beijing could use tensions to drive wedges between the United States and allies, while seeking tostrengthen ties with Washington and isolate its allies.

Policy Options and Congressional OversightPossible congressional actions or oversight of policy include legislation, hearings, and otheroptions that could focus on addressing the PRC’s ECS ADIZ, U.S. military contacts with the
PLA, strategic reviews of policy, crisis-management and confidence-building measures,

148

Edward Luttwak argues that China has a “prolonged outbreak of feckless nationalism and militarism that evokes thesinister precedent of pre-1914 Germany.” (“China’s Military Adventurism is Ill-Timed,” Wall Street Journal,
December 29, 2013.
149
Defense Department, Press Briefing by Secretary Hagel and Minister Ng, Pentagon, December 12, 2013.
150“Joint Statement of the ASEAN-Japan Commemorative Summit,” Vietnam News Agency, December 14, 2013
151
“ASEAN Cautious on Air Zone Debate,” China Daily, December 14, 2013
152
“China Must Rescind its Air Zone Over Disputed Islands,” Washington Post, November 25, 2013.
153“China’s Coercive Play,” New York Times, November 25, 2013.
154
Dan Blumenthal, American Enterprise Institute (AEI), writes that “Xi also intended to demonstrate to U.S. friends,
from Japan to the Philippines, that it will take coercive actions even as top U.S. leaders come to the region,” in “China
Tips Its Hand,” National Interest, December 5, 2013. Bonnie Glaser, testimony at a Hearing of the House Armed
Services Subcommittee on Seapower and Projection Forces and House Foreign Affairs Subcommittee on Asia and thePacific, “Maritime Sovereignty in the East and South China Seas,” January 14, 2014.

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international institutions and rules, alliances with Japan and South Korea, and standards andprocedures at the ICAO.

Proactive U.S. Policy
Alongside debates about whether Beijing’s declaration of the ECS ADIZ merits imposing costs ofsome kind, the issue also raised questions about the need for a more forward-looking, rather thanreactive, U.S. policy toward China. Such a policy might encourage China to pursue nonmilitarized measures and avoid intercepts by military ships or aircraft in order to reduce the risksof accidents and escalation. In early December, Vice President Biden told President Xi that theUnited States looks to China to lower tensions, to avoid ADIZ enforcement that could lead to acrisis, and to establish channels of communication with Japan and other countries to avoid therisk of mistake, miscalculation, accident, or escalation.155 In early 2014, Assistant Secretary ofState Russel stated, “In the short term, there is a crying need for a practical mechanism to prevent
crises or manage them should they occur. The critical thing in the short term is that no incident beallowed to trigger an escalatory cycle, and the environment and structures be put in place thatminimize the risk of an incident taking place at all.”156
At a U.S.-PRC summit in Beijing in November 2014, Presidents Obama and Xi announced twomemoranda of understanding (MOUs) as military-to-military confidence-building measures: an
MOU on the Notification of Major Military Activities and an MOU on the Rules of Behavior for
Safety of Air and Maritime Encounters (expanded to cover coast guards as well militaries). The
MOU on Rules of Behavior commits both sides to follow established international laws and rules,
rather than concluding new, binding, bilateral rules or agreements.157 The two sides issued anannex on surface-to-surface encounters between ships. Reflecting the greater difficultly in dealing
with air-to-air encounters and with the international laws that govern military aircraft, the twosides did not complete an annex on air-to-air encounters, but agreed to complete negotiations onthat annex in 2015.158 The U.S.-PRC announcement shows a mutual interest in avoiding
unplanned, dangerous encounters at sea and in the air. The MOU demonstrates a potential
outcome of discussions with PLA operational officers and top leaders about aviation safety andsecurity, military exchanges, and maritime law enforcement. However, some analysts contend
that the MOU does not address fundamental differences in the interpretation of international law
between the United States and China, and that many past encounters between ships and aircraft
were not “unplanned” but rather intentionally provocative.159 Further dialogues, including those atinternational legal or other forums, may be necessary to test whether Beijing is asserting its

155

White House, Background Briefing by Senior Administration Officials on Vice President’s Trip, Beijing, December
4, 2013.
156
Simon Denyer, “Obama’s Asia Rebalance Turns Into Headache as China, Japan Relations Spiral Down,”
Washington Post, January 23, 2014.
157
The MOU does not prejudice either side’s perspective on military activities permissible in EEZs. For more, see CRS
Report RL32496, U.S.-China Military Contacts: Issues for Congress, by Shirley A. Kan.
158
“Memorandum of Understanding between the Department of Defense of the United States of America and theMinistry of National Defense of the People’s Republic of China Regarding the Rules of Behavior for Safety of Air andMaritime Encounters,” signed November 9-10, 2014, in Washington, DC, and Beijing, China, U.S. Department of
Defense Publications, http://www.defense.gov/pubs/141112_MemorandumOfUnderstandingRegardingRules.pdf.
159Mark J. Valencia, “The US-China MOU on Air and Maritime Encounters,” The Diplomat blog, November 17, 2014,
http://thediplomat.com/2014/11/the-us-china-mou-on-air-and-maritime-encounters.

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claims based on international law or rules (such as international aviation practices in setting up
ADIZs), or on another basis.
Some analysts argue that quiet diplomacy might be more effective than public, high-profile
defiance that would goad China into a counter-productive hardening of its approach inannouncing the ECS ADIZ.160 The United States, however, was already pursuing a quiet
diplomatic approach prior to the announcement of the ECS ADIZ. For example, Washington andTokyo did not emphasize publicly the alliance’s coverage of the Senkaku Islands in a high-leveljoint statement in October 2013, demonstrating, perhaps, awareness of Beijing’s sensitivity to
public emphasis on the Senkaku/Diaoyu issue in U.S.-Japan joint statements.161 Days before theannouncement, National Security Advisor Susan Rice gave a speech in which she cited U.S.
concerns about the rise of maritime disputes in Asia, a growing threat to U.S. interests in peaceand security, but she did not reiterate that the U.S.-Japan defense treaty covers the Senkaku
Islands.162

Addressing the ECS ADIZ
Clarify Official U.S. Position on the ECS ADIZ
Congress could call for the Obama Administration to formulate a coherent, consistent, andcoordinated message about China’s ECS ADIZ, including clarification of (1) whether U.S.
airlines should file flight plans when entering the ECS ADIZ, and (2) the meaning of not
accepting officially the ECS ADIZ. S.Res. 412 states that the Senate “urges the Government of
the [PRC] to refrain from implementing the [ECS ADIZ], which is contrary to freedom of
overflight in international airspace ... ” The resolution reaffirms the strong support of the U.S.
Government for freedom of navigation and other internationally lawful uses of sea and airspace in
the Asia-Pacific region and states that it is U.S. policy, inter alia, to assure the continuity of U.S.
operations in that region. On December 3, 2014, the House of Representatives (113th Congress)
passed H.Res. 714, which states that the House does not recognize the PRC’s declared ECSADIZ, describes it as “contrary to freedom of overflight in international airspace,” and calls on
China to “refrain from taking similar provocative actions elsewhere in the Asia-Pacific region,
including in the South China Sea.”

Lead International Actions
Congress could urge the Obama Administration to lead a coordinated response with Japan, South
Korea, and perhaps Taiwan, and to prevent any attempts by China to use a “divide and conquer”
strategy to induce at least one party to cut a side deal (whereby Beijing ameliorates one party’s
particular grievance). Congress could call for the United States and its allies to continue or
increase combined military exercises in the region, including in the Yellow Sea and South China
Sea.163 Congress also could call on the Administration to lead efforts or support an ally’s proposal
160

For example: David Welch, “What’s an ADIZ” Foreign Affairs, December 9, 2013.
Joint “2+2” Statement issued by Secretary of State Kerry, Secretary of Defense Hagel, Minister for Foreign Affairs
Kishida, and Minister of Defense Onodera, of the U.S.-Japan Security Consultative Committee (SCC), Tokyo, October
3, 2013.
162
White House, “America’s Future in Asia,” Remarks by Susan Rice, Georgetown University, November 20, 2013.
163
Victor Cha, “The Opportunity for the U.S. in China’s Overreach,” Washington Post, December 6, 2013.
161

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for multilateral talks about the PRC’s ECS ADIZ or crisis management mechanisms. The UnitedStates might urge China to consult with other countries in advance of announcing any future
ADIZs in a way that would be in conformity with international norms.

Oppose Other PRC ADIZs
Congress could call on the Administration and other countries to oppose other ADIZs that the
PRC might seek to establish. S.Res. 412 and H.Res. 714 urge China to refrain from taking further
provocative actions similar to the ECS ADIZ announcement. After the PRC’s designation of the
ECS ADIZ, it appears that the Obama Administration began to take a more proactive position
pertaining to maritime disputes not only in the East China Sea but also the South China Sea. In
mid-December 2013, Secretary of State Kerry visited Hanoi and Manila, where he expressed
concerns about the ECS ADIZ announcement and declared that China should refrain from taking
similar unilateral actions elsewhere, particularly over the South China Sea.164 The State
Department’s spokesperson also said that the United States would consider an ADIZ over theSouth China Sea as a provocative and unilateral act that would raise tension.165
In February 2014, Assistant Secretary of State for East Asian and Pacific Affairs Daniel Russel
articulated a stronger Administration position in his testimony at a hearing of the House Foreign
Affairs Committee Subcommittee on Asia and the Pacific:
China’s announcement of an Air Defense Identification Zone (ADIZ) over the East China
Sea in November was a provocative act and a serious step in the wrong direction. The
Senkakus are under the administration of Japan and unilateral attempts to change the status
quo raise tensions and do nothing under international law to strengthen territorial claims. The
United States neither recognizes nor accepts China’s declared East China Sea ADIZ and has
no intention of changing how we conduct operations in the region. China should not attempt
to implement the ADIZ and should refrain from taking similar actions elsewhere in theregion.166

The Commander of the U.S. Pacific Air Forces said in early 2014 that any attempt by the PRC to
set up an ADIZ over the South China Sea would be very provocative and that the United Statesstrongly conveyed its opposition to such a move to the PRC.167 A senior NSC official asserted that
the United States would change its military deployments and force posture in the region if the
PRC set up another ADIZ.168 The NSC official did not provide specifics, but such a shift mightentail the deployment (rotational or permanent) of more U.S. military aircraft and othersurveillance and reconnaissance assets to Northeast Asia or Southeast Asia.

164

State Department, Joint Press Availability with Vietnamese Deputy Prime Minister and Foreign Minister Pham Binh
Minh, Hanoi, December 16, 2013; Remarks with Philippine Foreign Secretary Albert del Rosario, Manila, December
17, 2013.
165
State Department, Press Briefing, January 31, 2014.
166
House Foreign Affairs Subcommittee on Asia and the Pacific, “Maritime Disputes in East Asia,” February 5, 2014.
167
Sanat Vallikappen and Rosalind Mathieson, “U.S. General Tells Japan, Philippines to Cool China Rhetoric,”
Bloomberg News, February 10, 2014.
168
Jun Kaminishikawara, “U.S. could change military posture if China expands air defense zone,” Kyodo News
Agency, January 31, 2014.

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Operations to Assert Freedom of Navigation and Overflight
Congress could consider whether the Obama Administration’s articulation of heightened concern
about China’s challenges to access in international airspace and waters warrants follow-up
options to buttress the U.S. statements. Although U.S. military leaders have said that U.S. military
flights have continued without change after the PRC’s ECS ADIZ announcement, they have notbeen as publicized as the B-52 flights days after that announcement. Potential options forCongress include requesting reports or briefings on U.S. flights through the ECS ADIZ, on
preparations for aggressive interceptions of U.S. aircraft, and on U.S. support for allied countries’
military aircraft in the ECS ADIZ. The U.S. military conducts Freedom of Navigation (FON)
operations to challenge excessive maritime claims, in order to preserve the rights, freedoms, anduses of the sea and airspace under international law.169 The United States could reinforce its
rhetorical response to China with air and naval patrols in the East China Sea, perhaps in
combined operations with allies.170 S.Res. 412 (113th Congress) affirmed that it is U.S. policy to“assure the continuity of operations by the United States in the Asia-Pacific region, including,when appropriate, in cooperation with partners and allies, to reaffirm the principle of freedom of
operations in international waters and airspace in accordance with established principles andpractices of international law.”

Accommodation and Assurance of China
Some scholars advocate attention to accommodation bilaterally to avoid a relationship with amore adversarial, assertive, or aggressive China with rising military power.171 Other scholars urge
Washington to reassure Beijing, including by informing it in advance of legitimate U.S. militarytransits (though not necessarily particular flight plans) and to avoid flights by B-52 bombers infavor of fighters or patrol planes to assert the freedom of navigation and overflight in the ECS
ADIZ.172 Congress could encourage expanded and comprehensive political, economic, andmilitary engagement with the PRC to deal with tensions arising from episodes like theestablishment of the ECS ADIZ.

Military-to-Military Contacts with China
Concerning U.S. military-to-military contacts with China, Congress has oversight of the
President’s adherence to laws that include the National Defense Authorization Act (NDAA) for
FY2000 (P.L. 106-65), which restricts military-to-military exchanges, and the Arms Export
Control Act (AECA) (P.L. 90-629), which governs transfers of defense articles and defense
services. U.S. defense officials have expressed a desire to continue or intensify communication
with the PLA regarding the ECS ADIZ and other concerns. The Chief of Staff of the Air Force,
General Welsh, said that the disagreement over the ECS ADIZ is an opportunity for better
169

Department of Defense, “Freedom of Navigation (FON) Report for Fiscal Year (FY) 2013,” March 6, 2014.
Wallace Gregson and Joanna Yu Taylor, “Xi’s Air Defense Offense,” Center for National Interest, December 10,
2013.
171
Michael Swaine, “Avoiding U.S.-China Military Rivalry,” Diplomat, February 16, 2011; Zbigniew Brzezinski,“Balancing the East, Upgrading the West,” Foreign Affairs, January/February 2012; Kenneth Lieberthal and Stapleton
Roy, “Defuse the Distrust with Beijing,” Washington Post, February 13, 2012.
172
James Steinberg and Michael O’Hanlon, “China’s Air Defense Zone: The Shape of Things to Come?” Reuters, Dec.
16, 2013.
170

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communication.173 PACOM Commander Admiral Locklear called the PLA’s participation for the
first time in the Rim of the Pacific (RIMPAC) maritime exercise at Hawaii in the summer of 2014
a “confidence-building measure” to help prevent miscalculation and promote peace. The
Commander of the U.S. Pacific Air Forces, General Lori Robinson, attended China’s air show inNovember 2014. On the other hand, some observers call for disengaging from the trajectory ofcloser military exchanges.174 A third view calls for Congress to retract restrictions in the FY2000
NDAA that constrain contacts with China’s military and leave decisions to the executive branchabout how to carry out exchanges with the PLA.175

Strategic Reviews of Policy
The PRC’s designation of the ECS ADIZ again raises the question of whether the U.S. responses
to the PRC’s moves in maritime disputes have been effective and whether this development
warrants a broad review for any changes in policy. Such attention is consistent with calls amongsome Members of Congress and observers for a clearer strategy to implement theAdministration’s “rebalance” to the Asia-Pacific in a coordinated, comprehensive way. Section
1251 of the National Defense Authorization Act (NDAA) for FY2015 (P.L. 113-291) instructs the
Secretary of Defense to develop a strategy to prioritize U.S. defense interests in the Asia-Pacificregion. Section 1257 of the FY2015 NDAA requests an independent assessment of A2/AD
strategies and capabilities that pose a threat to security in the Asia-Pacific region and strategies tomitigate such threats.
Another option for congressional oversight concerns the development of an inter-agency strategy
for the rebalance to the Asia-Pacific region. Section 7043 of the Consolidated Appropriations Act
of FY2014 (P.L. 113-76) requires that the Secretary of State, in consultation with the
Administrator of the U.S. Agency for International Development (USAID), the Secretary of
Defense, and the heads of other relevant federal agencies, submit an integrated, multi-yearplanning and budget strategy for a rebalancing of U.S. policy in East Asia and the Pacific thatlinks U.S. interests with the necessary resources and personnel required for implementation,
management, and oversight of such a strategy.

Crisis-Management and Confidence-Building Measures
Congress could call for U.S. efforts, perhaps in coordination with allies and partners, to test
whether the PRC seeks stable ties and de-escalation of tension by suggesting crisis-management
mechanisms or confidence building measures (CBMs). The U.S. Defense Department set up a
direct defense telephone line (a hotline) with the PLA in 2008, after five years of negotiations.
Vice President Biden visited Asia right after the ECS ADIZ announcement and stressed that theaction underscored the need for China and Japan to establish CBMs to lower tensions.176 In 2012,
173

Aaron Mehta, “Chinese Air Defense ID Zone Shows Need for Communication,” Defense News, December 11,
2013.
174
Wallace Gregson and Joanna Yu Taylor, “Xi’s Air Defense Offense,” Center for National Interest, December 10,
2013; Dean Cheng, “Meeting the Challenge of Chinese Expansionism on the East Asian Littoral,” Heritage Foundation,
January 24, 2014.
175
Douglas Paal, “Contradictions in China’s Foreign Policy,” Carnegie Endowment, December 13, 2013.
176
Biden made the point before and during his visit. Yoichi Kato, “Japan, China Need Crisis Management
Framework,” Asahi Japan Watch, Tokyo, December 2; White House, Remarks by Vice President Biden and Prime
Minister Abe, December, 3, 2013.

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military officials of the PRC and Japan discussed setting up a hotline to prevent air and naval
crises, but the talks were suspended amid tension over the Senkaku Islands.177 Beijing resisted restarting talks on a maritime communication mechanism and strongly criticized Tokyo, but the twosides eventually returned to negotiations following the meeting of Prime Minister Abe andPresident Xi in November 2014.178
If negotiating new agreements is difficult, attention could be focused on implementing or
adjusting existing agreements, or resuming previously held dialogues. Examples include anagreement of February 13, 2001, whereby the PRC and Japan agreed on a mutual notification
system through which each side will notify the other prior to maritime research near the othercountry. The November 2014 U.S.-China MOU on the Rules of Behavior for Safety of Air andMaritime Encounters may be another model for China and Japan. Some China experts havequestioned the utility of hotlines, because the PLA has been reluctant to hold direct discussions intimes of international crises.179

One Model of International ADIZ Management: Japan-ROK Pact
Since 1995, Japan and South Korea have abided by a bilateral agreement to report in advance theflight plans of military aircraft that might stray into the other country’s ADIZ. Reportedly, the twocountries agreed on this notification pact in order to avoid accidental confrontations, build greater
confidence between the two countries and their militaries, and obviate unnecessary scrambles.180
Such an agreement might be a practical way for East Asian countries to manage some of thenegative consequences of their overlapping and contested ADIZs. However, it is unlikely thatJapan and China would agree to reciprocal notification of military flights in the other country’s
ADIZ, because that could be construed as acceptance of the other’s ADIZ.

Recalibrating the U.S.-Japan Alliance
The United States may choose to recalibrate, in small but significant ways, its alliancerelationship with Japan (and perhaps South Korea) partly in response to the establishment of the
PRC’s ECS ADIZ. Potential alliance adjustments could take the form of new military operational
practices, official rhetoric, defense cooperation guidelines, or other policies. Before his April
2014 trip to Japan, President Obama announced, “The policy of the United States is clear—the
Senkaku Islands are administered by Japan and therefore fall within the scope of Article 5 of the
U.S.-Japan Treaty of Mutual Cooperation and Security. And we oppose any unilateral attempts toundermine Japan’s administration of these islands.” A Sense of the Congress in Section 1286 of
the FY2013 NDAA (P.L. 112-239) states, “The unilateral action of a third party will not affect theUnited States’ acknowledgment of the administration of Japan over the Senkaku Islands.” S.Res.
412 echoed this statement. U.S. officials could choose to consistently reiterate that Article 5 of the
U.S.-Japan treaty applies to the Senkaku Islands and the surrounding 12-nm of sea and airspace.
On the other hand, U.S. officials may also decide to keep ambiguous the conditions under which
the treaty would apply.
177“Japan-China Defense Communication Talks Suspended Due To Row,” Kyodo News Agency, October 26, 2012.
Sachiko Miwa, “Analysis: Hotline with China only first step toward avoiding military incident,” Asahi Shimbun,
November 18, 2014.
179“China-U.S. Defense Hotline Shows Gulf as Military Chief Visits,” Bloomberg News, May 13, 2011.
180“Japan, ROK Finalize No-Scramble Pact,” Jiji Wire Service, June 5, 1995.
178

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37China’s Air Defense Identification Zone (ADIZ)The ongoing revision of the U.S.-Japan Mutual Defense Guidelines, which provide a policy
framework for security cooperation, could clarify U.S.-Japan combined activities in the East
China Sea, including air operations in the disputed ADIZ. A small number of outside observers
have suggested that the United States should consider recognizing Japanese sovereignty over the
Senkaku islands as a way to provide clarity and to bolster the U.S.-Japan alliance.181 Anotheroption would be to foster trilateral defense coordination among the United States, Japan, andSouth Korea, as a way to discourage provocative actions from the PRC (and North Korea). Still,policy makers might reserve options for the future after testing Beijing to see whether it is serious
about lowering tension with other countries or is raising tensions to strengthen its stance, andwhether China increasingly is acting in accordance with international laws.

International Rules and Arbitration
Congress could urge the Obama Administration to focus on options that consider internationalrules or mechanisms for dispute resolution, including referral to the International Court ofJustice.182 U.S. officials at the highest levels consistently raise concerns about the need for arules-based, less confrontational international regime for both the South and East China Seas,
including how the PRC might or might not set up another ADIZ.183 There are several forums
available to arbitrate maritime territorial disputes, such as the Senkaku/Diaoyu islands disputethat arguably was the genesis of the ECS ADIZ. Yet, the principles governing the scope andapplication of ADIZs have not been defined in international law (see next section).

Addressing ADIZs at ICAOICAO was created under the 1944 Chicago Convention to serve as the designated United Nations
agency charged with matters pertaining to international aviation. ICAO develops international
standards and recommended practices for aviation. In this capacity, ICAO appears to be the mostappropriate authority for hearing concerns regarding the establishment of and procedural
requirements for ADIZs.184 As previously noted, however, neither the Chicago Convention nor
ICAO standards and recommended practices specifically address issues pertaining to ADIZs. The
United States or any other member nation could petition ICAO or take a lead role in proposing
and drafting a proposed ICAO standard or recommended practice pertaining to the establishmentof ADIZs and flight operational procedures within a designated ADIZ. As a possible option,
Members of Congress could urge that the U.S. Mission to ICAO work with other ICAO member
nations toward a consensus agreement with regard to ADIZs. An international agreement could
offer predictability and prevent the proliferation of ADIZs that increase the risks of conflict.
However, U.S. accession to such an agreement could force changes in U.S. ADIZ practices andlimit the scope for unilateral management of airspace near U.S. territory.

181

For example, in oral testimony to the House Armed Services Subcommittee on Seapower and Projection Forces on
February 27, 2014, Ely Ratner suggested, “We can think about – and this would be incredibly sensitive, but in a – incertain contexts revisiting our neutrality on certain sovereignty issues.”
182
Kishore Mahbubani, “How to Prevent a War Between China and Japan,” Bloomberg, December 29, 2013.
183
See, for example, Secretary of State John Kerry, Solo Press Availability, Beijing, China, February 14, 2014.
184
Roncevert Almond, “Troubled Skies above the East China Sea,” The Diplomat, November 24, 2014,
http://thediplomat.com/2014/11/troubled-skies-above-the-east-china-sea/.

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China’s Air Defense Identification Zone (ADIZ)ICAO offers a process for international dispute resolution regarding matters pertaining tointernational aviation, including potentially the ongoing dispute over China’s ADIZ. In December
2013, it was reported that Japan requested ICAO involvement in resolving the dispute over
China’s ADIZ.185 In March 2014, the United States and Japan formally submitted a letter to ICAO
asking whether a country has the right to give orders to, or restrict the flights of, commercial
aircraft in airspace outside the jurisdiction of its civilian air traffic controllers.186 As noted earlier,a large portion of the ECS ADIZ extends beyond Chinese-controlled FIRs, though that is not the
only aspect of the ADIZ to which the United States and Japan have objected. A possible future
course of action for countries opposing China’s establishment of or procedural requirements forcivil aircraft flying in its ECS ADIZ would be to file a formal complaint before ICAO in what isreferred to as an Article 84 filing. Article 84 of the Chicago Convention establishes a formal
ICAO process for settling differences among member countries.
Since ADIZs are not formally recognized under the Chicago Convention or international civil
aviation law, there is no clear precedent for how ICAO may resolve such a complaint. The
outcome may have important implications for international recognition of ADIZs globally,
including long-established ADIZs, such as those maintained by the United States. Central issues
for a possible international debate on ADIZs are likely to include the extent of ADIZ boundaries
beyond territorial airspace, the applicability of ADIZ procedures to transiting aircraft notintending to enter sovereign airspace, and potential operational conflicts in areas where ADIZs
overlap.

Outlook
Although the issue of ADIZs is not central to U.S.-China relations or to China’s overall foreignand defense policies, the PRC’s actions regarding the ECS ADIZ and its decisions to designate (ornot) other ADIZs will continue to shape perceptions of China and influence the narratives
surrounding its rise to major power status. In particular, the PRC’s handling of any new ADIZ,
should it choose to designate one, will be watched very closely for what it says about Chinese
attitudes toward its neighboring countries and toward the rules and norms of the existing
international order. Congress and the executive branch likely will calibrate U.S. policy toward the
PRC based in part on Beijing’s actions in its maritime periphery, and the ADIZ issue now figuresin that policy analysis. In a more narrow sense, the PRC’s approach to the Senkaku/Diaoyu Island
dispute will also influence how observers interpret the decision to designate the ECS ADIZ in late2013. If China uses the ECS ADIZ as an instrument to increase pressure on Japan and the U.S.Japan alliance, that may suggest that Beijing’s goals were not defensive but rather coercive innature.

185

Lars Nicolaysen, “Japan Asks the World Air Regulator To Act Over China’s Air Defence Zone In the East China
Sea,” The Sydney Morning Herald (Australia), December 2, 2013, http://www.smh.com.au/world/japan-asks-theworld-air-regulator-to-act-over-chinas-air-defence-zone-in-the-east-china-sea-20131201-2yjgo.html.
186“Japan, U.S. Refer China’s ADIZ to ICAO,” Jiji Wire Service, March 11, 2014.

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Appendix. Text of ECS ADIZ Announcement
The PRC MND issue the following statement on November 23, 2013:
The Ministry of National Defense of the People’s Republic of China, in accordance with theStatement by the Government of the People’s Republic of China on Establishing the East
China Sea Air Defense Identification Zone, now announces the Aircraft Identification Rules
for the East China Sea Air Defense Identification Zone as follows:First, aircraft flying in the East China Sea Air Defense Identification Zone must abide bythese rules.
Second, aircraft flying in the East China Sea Air Defense Identification Zone must provide
the following means of identification:
1. Flight plan identification. Aircraft flying in the East China Sea Air Defense
Identification Zone should report the flight plans to the Ministry of Foreign Affairs of thePeople’s Republic of China or the Civil Aviation Administration of China.
2. Radio identification. Aircraft flying in the East China Sea Air Defense Identification
Zone must maintain the two-way radio communications, and respond in a timely andaccurate manner to the identification inquiries from the administrative organ of the East
China Sea Air Defense Identification Zone or the unit authorized by the organ.
3. Transponder identification. Aircraft flying in the East China Sea Air Defense
Identification Zone, if equipped with the secondary radar transponder, should keep thetransponder working throughout the entire course.
4. Logo identification. Aircraft flying in the East China Sea Air Defense Identification
Zone must clearly mark their nationalities and the logo of their registration identificationin accordance with related international treaties.
Third, aircraft flying in the East China Sea Air Defense Identification Zone should follow the
instructions of the administrative organ of the East China Sea Air Defense Identification
Zone or the unit authorized by the organ. China’s armed forces will adopt defensive
emergency measures to respond to aircraft that do not cooperate in the identification or
refuse to follow the instructions.
Fourth, the Ministry of National Defense of the People’s Republic of China is theadministrative organ of the East China Sea Air Defense Identification Zone.
Fifth, the Ministry of National Defense of the People’s Republic of China is responsible forthe explanation of these rules.
Sixth, these rules will come into force at 10 a.m. November 23, 2013.187

187“Announcement of the Aircraft Identification Rules for the East China Sea Air Defense Identification Zone of the
P.R.C.,” PRC Ministry of National Defense, November 23, 2013, http://eng.mod.gov.cn/Press/2013-11/23/
content_4476143.htm.

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Author Contact Information
Ian E. Rinehart
Analyst in Asian Affairs
irinehart@crs.loc.gov, 7-0345

Bart Elias
Specialist in Aviation Policy
belias@crs.loc.gov, 7-7771

Acknowledgments
Several portions of this report are based on material authored by retired CRS Specialist in Asian Security
Affairs Shirley Kan.

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