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Prepared by: USINDOPACOM Joint Operational Law Team (J06.pacom@pacom.mil) 

Last Updated: 8 May 2023 (all prior versions obsolete)

**This TACAID includes legal opinion and analysis that does not necessarily reflect official U.S. government positions

USINDOPACOM J06/SJA TACAID SERIES 

TOPIC: LAWFUL SEA CONTROL TO PROTECT SEA LINES OF 

COMMUNICATION AND CHOKEPOINTS

BLUF • In the event of armed conflict and in collaboration with allies and partners (A&P),

i U.S. forcesii are willing and able 

to safeguard navigational freedoms and protect global sea lines of communication (SLOCs) and chokepoints. 

• SLOCs are the principal maritime routes between ports used for trade, military, or other purposes. Chokepoints 

are constricted passageways (e.g., straits) that separate oceans and seas; they are relatively narrow, heavily 

trafficked, and sometimes in regions vulnerable to instability.

• The naval concept applicable to protecting/securing SLOCs and chokepoints is known as sea control. When 

necessary during armed conflict, lawful sea control may deny or limit an adversary’s ability to threaten SLOCs and 

chokepoints or use them for war-supporting shipping.

iii 

• Lawful sea control allows U.S. and A&P forces to preserve navigational rights, prevent unlawful interference, and if

necessary and in accordance with international law, deny or limit an adversary’s use of SLOCs and chokepoints. 

• As an aspect of sea control during armed conflict, protection of SLOCs and chokepoints ensures critical waterways 

remain open for trade and freedom of navigation, but shielded from hostilities by adversaries and non-neutral 

commerce (e.g., contraband or war-sustaining or war-supporting shipping). 

• Potential threats to SLOCs and chokepoints underscore the importance of U.S. and A&P ability to exercise sea 

control across a spectrum of scenarios.

WHY THIS MATTERS TO YOU • Sea control ensures vital SLOCs and chokepoints remain open in crisis and conflict, but are not used by an adversary 

to sustain or support a war effort that jeopardizes international peace and security. 

• Understanding international law underpinning sea control helps to identify and illuminate when an attempt to 

exercise sea control is contrary to international law, such as when a state unlawfully interferes with other states’ 

exclusive economic zone (EEZ) rights; asserts excessive maritime claims; or causes dangerous interactions with 

foreign vessels and aircraft lawfully operating in international waters and airspace. 

DETAILED DISCUSSION

SEA CONTROL DEFINED

• Sea control is the essence of sea power and a necessary ingredient in successful 

accomplishment of all naval missions,

iv enabling effectiveness and speed of maneuver.v

• U.S. Sea Services define sea control as: “the condition in which one has freedom of action 

to use the sea for one’s own purposes in specified areas and for specified periods of time 

and, where necessary, to deny or limit its use to the enemy [during conflict]. Sea control 

includes the airspace above the surface and the water volume and sea floor below.”vi 

• Many U.S. allies and partners share a similar definition or conceptualization.vii 

• Examples of sea control may include naval cooperation and guidance for shipping, 

blockades, embargoes, maritime interception operations (MIO), and protection of sea 

and air lines of communication.

viii

• Sea control is both established by, and an enabler of, all-domain activities.ix

U.S. Tri-Service Maritime 

Strategy (2020)
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IMPORTANCE OF SEA CONTROL

• During armed conflict. Sea control operations are those operations designed to secure use of the maritime domain 

by one’s own forces and to prevent its use by the enemy.x Sea control, particularly of SLOCs and chokepoints, is 

essential to military victory. The U.S. tri-Service maritime strategy reaffirms that sea control is a critical enabler:

o Sea control enables lawful use of the sea to flow forces and materiel, project power, and conduct other 

essential activities: “Establishing sea control is a critical enabler for all other naval missions that support the 

Joint Force, including power projection and sealift.”xi

o At the same time, sea control may entail lawful denial of an adversary’s use of the seas: “Where adversaries 

must cross open water, sea denial robs them of the initiative, impedes a fait accompli, and prevents them 

from achieving their objectives. We control or deny the seas by destroying an adversary’s fleet, containing 

it in areas that prevent meaningful operations, prohibiting it from leaving port, or by controlling sea lines 

of communication.”xii

o Additionally, “in collaboration with allies and 

partners, we will be capable of controlling critical 

choke points, enabling us to safeguard joint 

forces flowing into theater and to impose 

military and economic costs on our 

adversaries.”xiii 

o During armed conflict, under international law, 

warships may exercise various belligerentxiv

rights at sea to establish sea control or project 

power as a function of sea control:

xv

 Disrupt, neutralize, capture, or destroy 

enemy warships and military aircraft, including naval and military auxiliaries, beyond neutral 

territory.xvi 

 Attack and destroy enemy merchant vessels, as valid military objectives by their nature, purpose, 

use, war-sustaining, or war-supporting roles.xvii 

 Disrupt non-neutral shipping (i.e., carrying contrabandxviii or war-sustaining commercexix). 

 Prevent enemy forces from using neutral waters as a sanctuary or base of operations when the 

neutral state is unwilling or unable to detect and expel those enemy forces.xx 

 Assure compliance by others with the law of neutrality.xxi

 Control neutral vessels/aircraft in the immediate vicinity of naval operations.xxii 

 Establish and enforce a blockade.xxiii 

 Establish and enforce an exclusion zone.xxiv

o Exercises of sea control must comply with the law of armed conflict. For example:

 Only military objectives may be attacked.xxv

 A blockade is prohibited if the sole purpose is to starve the civilian population or deny it other 

objects essential for its survival.xxvi

 Neutral merchant vessels and civil aircraft engaged in legitimate neutral commerce are subject to 

visit and search, but may not be captured or destroyed by belligerent forces.xxvii

 Acts of hostility in neutral waters/airspace are prohibited.xxviii

 Forces transiting through international straits overlapped by neutral waters must proceed without 

delay and otherwise refrain from acts of hostility and other activities not incident to their transit. 

Neutral straits may not be used as a base of operations and belligerent warships may not exercise 

the belligerent right of visit and search in those waters.xxix

 Naval mines may not be emplaced off the coasts and ports of the enemy with the sole objective of 

intercepting commercial shipping.xxx

 Neutral states may not close or impede passage through archipelagic sea lanes or international 

straits overlapped by territorial seas. Belligerent vessels enjoy a right of unimpeded archipelagic 

sea lanes passage or transit passage, respectively, through these lanes/straits.xxxi

U.S. Navy alongside Japanese and Canadian forces

(Source: U.S. Navy)
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• Outside of armed conflict. Although sea control is often associated with armed conflict, during situations outside 

of armed conflict:

o Sea control enables crucial peacetime missions, e.g., responding to disasters, preserving maritime security, 

safeguarding global commerce, law enforcement, countering piracy, 

and protecting human life.xxxii

o Sea control also helps protect those missions from unlawful 

interference by others.xxxiii

o Presence operations; freedom of navigation operations; routine 

transits of international straits; and maritime warning zones are a few 

examples of peacetime sea control in that they set (or preserve) 

conditions for global mobility and freedom of action during peacetime. 

o During peacetime, it is also important for forces to train to lawfully 

exercise sea control and belligerent rights during armed conflict. 

o Lawful peacetime sea control should not be confused as unlawful 

exclusion or infringement on freedom of navigation and other maritime rights under international law. To 

the contrary, U.S. operations are conducted in accordance with international law and due regard for others’ 

safety, freedom of navigation, and other lawful uses of the sea and airspace: 

 Examples: U.S. forces may declare lawful “warning” zones (distinguished from unlawful “closure” 

areas) during peacetime operations in international waters for safety, security, and force 

protection, while also respecting others’ navigational rights and freedoms.

xxxiv

xxxvi

xxxvii

xxxviii

 The U.S. recognizes 

the rights of other states in waters off its coast when exercised in accordance with international 

law,

xxxv unlike some states that purport to unlawfully restrict innocent passage through territorial 

seas or military exercises in EEZs. The U.S. maintains a freedom of navigation program to 

challenge excessive maritime claims and preserve freedom of navigation enjoyed by (and 

benefiting) all nations. The U.S., allies, and partners exercise lawful sea control to help enforce 

sanctions against North Korea and its illicit nuclear/ballistic missile programs pursuant to U.N. 

Security Council resolutions and to deny use of the seas to for those illicit purposes.

 Compare: The PRC attempts to assert sea control that is contrary to international rules and norms 

and through coercion/intimidation. For example: military exercises in the Taiwan Strait that impede 

freedom of navigation by disrupting/diverting commercial shipping;xxxix

xliii

dangerous intercepts of 

aircraft operating lawfully in international airspace;xl repeated interference with routine resupply 

missions to a Philippine outpost in the Philippine’s EEZ;xli attempts to control and/or unlawfully 

interfere with other countries’ EEZs;xlii legally baseless claims (e.g., “9 dash-line”) to wide swaths of 

the South China Sea; maritime jurisdiction claims that exceed what international law permits;

and other excessive claims.xliv

o U.S. capability and willingness to exercise sea control with A&P helps deter crisis/conflict – i.e., it is an 

important element of integrated deterrence to preserve peace, stability, and a free and open Indo-Pacific.xlv

APPLICATION OF SEA CONTROL TO SLOCs AND CHOKEPOINTS

• SLOCs & Chokepoints Defined. Sea lines of communication, or “SLOCs,” are the principal maritime routes between 

ports, as used for trade, military, or other purposes. SLOCs are, in a sense, maritime highways running through 

both open oceans and narrower maritime areas. A maritime “chokepoint” is a constricted marine passageway 

(usually between land areas, like a strait) that separates oceans and seas.

xlvii

xlvi Chokepoints are relatively narrow, 

heavily trafficked, and in some instances located in regions vulnerable to geopolitical instability.

• Importance of Sea Control to Protect and Deny. Protection of SLOCs and chokepoints is a critical aspect and 

purpose of sea control. During armed conflict, for example, the exercise of sea control ensures these critical 

waterways remain open for U.S. and A&P military activities, supply lines, and neutral commerce.xlviii At the same 

time, sea control denies an adversary’s ability to use SLOCs and chokepoints to conduct hostilities and for other 

belligerent purposes, and allows for the imposition of economic costs by denying the adversary’s use for nonneutral commerce (e.g., carrying contraband or otherwise sustaining/supporting the adversary’s war effort).xlix 

U.S. and Japan Coast Guard Vessels

(Source: DVIDS)
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• Threats to SLOCs & Chokepoints. The PRC could pose a threat to SLOCs and chokepoints through its “strategy and 

revisionist approach that...seeks to corrode international maritime governance, deny access to traditional logistical 

hubs, inhibit freedom of the seas, [and] control use of key chokepoints....”l

o Threat example: The PRC’s military drills in the Taiwan Strait following former U.S. Speaker of the House 

Nancy Pelosi’s visit to Taiwan threatened the free flow of commerce in a key SLOC, causing diversions and 

disruptions in shipping and impacts to the global economy.li

 U.S. and A&P transits through the Taiwan 

Strait, which encompasses a corridor of international waters and international airspace, help preserve 

freedom of navigation in the Strait and deter attempts at unlawful control.lii 

o Threat example: The PRC’s excessive maritime claims and construction of artificial islands and military 

outposts in the South China Sea (SCS) are meant to deny access to key SLOCs through the SCS and prevent 

others from exercising navigational freedoms.

liii U.S. freedom of navigation operations in the SCS challenge 

excessive maritime claims, and therefore preserve global mobility in this critical ocean area.

liv 

• Bottom Line. These sorts of threats to SLOCs/chokepoints underscore the importance of U.S. and A&P willingness 

and ability to exercise sea control across a spectrum of scenarios. 

PROPOSED COUNTER-LAWFARE APPROACH

**This section provides suggested language that may be incorporated into communication strategies that counter false legal narratives**

• In the event of armed conflict and in collaboration with A&P, U.S. forces are willing and able to safeguard 

navigational freedoms and protect global sea lines of communication (SLOCs) and chokepoints. 

• U.S. and A&P forces exercise lawful sea control to preserve navigational rights, prevent unlawful interference, and 

if necessary and in accordance with international law, deny or limit an adversary’s use of SLOCs and chokepoints.

• Protection of SLOCs and chokepoints ensures critical waterways remain open for trade and freedom of navigation, 

but shielded from hostilities and adversary use for war-supporting commerce. 

• U.S. forces operate together with A&P to counter effortsto corrode international maritime governance, deny access 

to traditional logistical hubs, and inhibit freedom of the seas. 

• Understanding international law underpinning sea control helps to identify and illuminate when an attempt to 

exercise sea control is contrary to international law, such as when a state unlawfully interferes with other states’ 

exclusive economic zone (EEZ) rights; asserts excessive maritime claims; or causes dangerous interactions with 

foreign vessels and aircraft lawfully operating in international waters and airspace.

i See, e.g., Australia Navy (“Sea Control is an essential precursor for the projection of maritime power, especially for the conduct of amphibious and sea transport operations and for the support 

of forces operating ashore.”), https://www.navy.gov.au/media-room/publications/semaphore-09-07; ROK Navy (importance of protecting sea lines of communication), 

http://www.navy.mil.kr/mbshome/mbs/navy/subview.do?id=navy_010400000000; U.K. Navy (“The majority of maritime trade passes through a handful of global chokepoints. We position 

our strength to safeguard these vital areas, promising safe passage and encouraging free trade...We are prepared to deploy rapidly across the globe...both in peacetime and in wartime....One 

of our greatest strengths is our ability to operate effectively by sea....”), https://www.royalnavy.mod.uk/what-we-do/; Seo-Hang Lee, SLOC Security in Northeast Asia: Korean Navy's Role, in

Dalchoong Kim and Doug-Woon Cho ed., Korean Sea Power and the Pacific Era, Institute of East and West Studies (1990); Japan Maritime Self Defense Force, Mission of JMSDF (noting 

importance of maritime operations, including presence, patrols, and reconnaissance to achieve wide-range of goals including protection of sea lanes, promotion of maritime security, defending 

Japan, countering piracy, and countering unilateral challenges to freedom of the oceans and navigation, both in peacetime and contingencies), https://www.mod.go.jp/msdf/en/about/role/. 

ii See Advantage at Sea: Prevailing With Integrated All-Domain Naval Power, USN/USMC/USCG (2020) at 27, https://media.defense.gov/2020/Dec/16/2002553074/-1/1/0/TRISERVICE

STRATEGY.PDF [hereafter Tri-Service Maritime Strategy]; DoD Joint Publication (JP) 3-32, Joint Maritime Operations (Sep. 20, 2021), available at https://www.jcs.mil/Portals/36/Documents/

Doctrine/pubs/jp3_32ch1.pdf?ver=LB2ScYW4n1KjS-mvwho3eg%3d%3d [hereafter JP 3-32]; U.S. Navy, Chief of Naval Operations, Navigation Plan (2022) at 6, https://media.defense.gov/2022/

 

Shipping Lanes, Chokepoints, and Increased Threats

(Source: U.S. Navy, Chief of Naval Operations, Navigation Plan (2022))
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 Jul/26/2003042389/-1/-1/1/NAVIGATION%20PLAN%202022_SIGNED.PDF [hereafter U.S. Navy NAVPLAN 2022].

iii See examples note ii supra. Many of our ally and partner maritime strategies also emphasize cooperation to exercise sea control to, for example, protect key SLOCs and promote maritime 

security, freedom of navigation, a free and open Indo-Pacific, and other shared interests. 

iv JP 3-32, supra note i.

v See Tri-Service Maritime Strategy, supra note i, at 16 (noting that naval forces and platforms, enabled by sea control, “increase our offensive lethality and speed of maneuver....”) (emphasis 

added). 

vi Id. at 27. Related to sea control is the concept of “sea denial,” i.e., partially or completely denying the adversary the use of the sea with a force that may be insufficient to ensure the use of 

the sea by one’s own forces. Id. at 27; see also Australia DoD, Sea Power Centre – Australia, Australia’s Need for Sea Control, Semaphore (Issue 9, 2007) [hereafter Australia Sea Control] 

(“Related to Sea Control is the concept of Sea Denial. Sea Denial may be used either independently or as a subset of Sea Control. When used on its own it can be defined as ‘the capacity to 

deny an adversary the ability to use the sea for their own purposes for a period of time without necessarily being able to exploit the sea for one's own use.’), https://www.navy.gov.au/mediaroom/publications/semaphore-09-07.

vii See, e.g., Australia Sea Control, supra note vi. The concept and importance of sea control has long been extolled by great naval strategists/theorists such as Mahan and Corbett. “[W]ars 

arising from other causes have been greatly modified in their conduct and issue by the control of the sea.” A. T. Mahan, The Influence of Sea Power Upon History, 1660-1783 (1890); see also

R. C. Rubel, Command of the Sea: An Old Concept Resurfaces in a New Form, 75 Nav. War Coll. 21 (2022); R. C. Rubel, Talking About Sea Control, 63 Nav. War Coll. 38 (2010).

viii JP 3-32, supra note i, at ix.

ix As the Tri-Service Maritime Strategy notes, all-domain operations help establish sea control: “Leveraging our interoperable C2 networks, allies and partners provide all-domain fires to help 

establish sea control and project power.” Id. at 14 (emphasis added). Likewise, sea control enables a range of synchronized, all-domain activities: “[b]y synchronizing the capabilities, capacities, 

roles, investments, and authorities of the Naval Service, we will expand our influence across the competition continuum and in all domains—from the sea floor to space; across the world’s 

oceans, littorals, and coastal areas ashore; and in the cyber domain, information environment, and electromagnetic spectrum.” Id. at 21 (emphasis added). Ultimately, all-domain operations 

enabled by sea control support combatant commanders with flexible response options. See id. at 10-11. 

x JP 3-32, supra note i, at I-3; U.S. Navy NAVPLAN 2022, supra note i, at 6 (“Sea control provides freedom of maneuver to the Joint Force and our allies while denying it to our enemies in conflict. 

Our ability to project power deters aggression by convincing rivals they have no viable means of achieving their objectives through force.) (emphasis added).

xi Tri-Service Maritime Strategy, supra note i, at 16.

xii Id. at 13.

xiii Id.

xiv A belligerent is essentially a party to an armed conflict.

xv A few examples follow in the body. For more on belligerent rights at sea during armed conflict, see The Commander’s Handbook on the Law of Naval Operations, NWP 1-14M/MCTP 11-

10B/COMDTPUB P5800.7A (2022 ed.) [hereafter LONO Handbook], including chapters 7 and 8, and the DoD Law of War Manual (updated May 2016), including chapters XIII and XV. 

xvi LONO Handbook, ¶¶ 8.6.1, 7.5.1.

xvii Id. at ¶ 8.6.2.

xviii Contraband consists of goods destined for an enemy and may be susceptible to use in armed conflict. Id. at ¶ 7.4.1.

xix “Contraband” consists of goods destined for the enemy and may be susceptible to use in armed conflict. Id. “War-sustaining commerce” is commerce that indirectly, but effectively supports 

and sustains the enemy’s warfighting capability, such as imports of raw materials used for production of armaments and exports of products the proceeds of which are used by the enemy to 

purchase arms and armaments. Id. at ¶ 7.4.

xx Id. at ¶ 7.3 et seq. 

xxi Id. at Ch. 7.

xxii Within the immediate area of naval operations (e.g., in the vicinity of naval units to ensure proper battlespace management and self–defense objectives), a belligerent may establish special 

restrictions upon the activities of neutral vessels and aircraft and may prohibit such vessels and aircraft from entering the area. The immediate area of naval operations is that area within

which hostilities are taking place or belligerent forces are operating. Belligerent control over neutral vessels and aircraft within an immediate area of naval operations is based on a belligerent’s 

right to attack and destroy its enemy, its right to defend itself without suffering from neutral interference, and its right to ensure the security of its forces. A belligerent may not purport to 

deny access to neutral States or close an international strait to neutral shipping, pursuant this authority, unless another route of similar convenience remains open to neutral traffic. The 

commanding officer of a belligerent warship may exercise control over the communication of any neutral merchant vessel or civil aircraft whose presence in the immediate area of naval

operations might otherwise endanger or jeopardize those operations. Id. at ¶ 7.8.

xxiii A “blockade” is an operation to prevent vessels and/or aircraft of all States, enemy and neutral, from entering or exiting specified ports, airfields, or coastal areas belonging to, occupied by, 

or under the control of an enemy State. Id. at ¶ 7.7 et seq. 

xxiv Such zones serve to warn neutral vessels and aircraft away from belligerent activities and thereby reduce their exposure to collateral damage and incidental injury, and to the extent that 

they do not unreasonably interfere with legitimate neutral commerce, they are undoubtedly lawful. Because exclusion zones and war zones are not simply ‘free-fire zones’ for the warships 

of the belligerents, the establishment of such a zone carries with it certain obligations for belligerents with respect to neutral vessels entering the zone. Id. at ¶ 7.9.

xxv Military objectives are those objects which, by their nature, location, purpose, or use, effectively contribute to the enemy’s warfighting, war-supporting, or war-sustaining capability and 

whose total or partial destruction, capture, or neutralization would constitute a definite military advantage to the attacker under the circumstances at the time of the attack. Id. at ¶¶ 5.3.1, 

8.2, 8.2.5.

xxvi Id. at ¶ 7.7.2.5. 

xxvii Neutral commerce comprises all commerce between one neutral State and another not involving materials of war or armaments ultimately destined for a belligerent State, and all commerce 

between a neutral State and a belligerent that does not involve the carriage of contraband or otherwise contribute to the belligerent’s warfighting/war-sustaining capability. Id. at ¶ 7.4.

xxviii Id. at ¶ 7.3.

xxix Id. at ¶ 7.3.6.

xxx Id. at ¶ 9.2.3. 

xxxi Id. at ¶¶ 7.3.6, 7.3.7.

xxxii See, e.g., Tri-Service Maritime Strategy at 7; id. at Ch. 3-4.

xxxiii For example, PRC fighter aircraft have conducted unsafe and unprofessional intercepts of U.S., ally, and partner aircraft (e.g., Canada, Australia) operating in international airspace during 

peacetime to help to enforce U.N. sanctions on North Korea for its illicit and destabilizing nuclear weapons and ballistic missiles programs and to conduct other peacetime activities. Brad

Lendon, Canada says Chinese Warplanes are Buzzing its North Korea Reconnaissance Flights, CNN (Jun. 6, 2022), https://www.cnn.com/2022/06/01/asia/canada-china-fighter-jet-harassmentintl-hnk-ml/index.html; Brad Lendon, Chinese fighter jet ‘chaffs’ Australian plane near South China Sea, Canberra alleges, CNN (Jun. 7, 2022), https://www.cnn.com/2022/06/05/australia/

australia-china-plane-intercept-intl-hnk-ml/index.html. 

xxxiv See LONO Handbook, supra note xv, ¶ 4.4.7; compare C. Parmley & R. P. Pedrozo, Russia’s Illegal Restriction of Navigation in the Black Sea, Lawfare (Apr. 27, 2021) (“To the extent the 

Russian closure area purports to close portions of the Black Sea that are beyond the 12 nautical mile boundary, it is inconsistent with international law”). 
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 xxxv See U.S. Statement on United States Oceans Policy (1983) (“The United States will recognize the rights of other states in the waters off their coasts, as reflected in [UNCLOS], so long as the 

rights and freedoms of the United States and others under international law are recognized by such coastal states.”). 

xxxvi The PRC, for example, purports to require prior notice or permission for innocent passage by foreign warships or military ships through its territorial sea. The PRC also claims a right to 

regulate foreign military activities in its EEZ. These are excessive maritime claims, contrary to law of the sea, and impede freedom of navigation. See U.S. Navy, Maritime Claims Reference 

Manual, available at https://www.jag.navy.mil/organization/

code_10_mcrm.htm. 

xxxvii Fact Sheet: U.S. Department of Defense Freedom of Navigation Program (Mar. 2015), https://policy.defense.gov/Portals/11/Documents/gsa/

cwmd/DoD%20FON%20Program%20--%20Fact%20Sheet%20(March%202015).pdf. 

xxxviii See, e.g., U.N. Sec. Res. 2627 (2022), 2397 (2017), 2375 (2017), 2321 (2016), 2094 (2013), 2087 (2013), 1695 (2006); note xxiii supra; K. Crummitt, U.S. Dep’t of State, Dipnote: Nations 

Collaborate to Prevent North Korea from Evading UN Sanctions (Apr. 15, 2022), https://www.state.gov/dipnote-u-s-department-of-state-official-blog/nations-collaborate-to-prevent-northkorea-from-evading-un-sanctions/; U.S. 7th Fleet Enforcement Coordination Cell Visits Partner Nations, FS Tonnerre, https://www.pacom.mil/Media/News/News-ArticleView/Article/2664969/us-7th-fleet-enforcement-coordination-cell-visits-partner-nations-fs-tonnerre/; UK Min. of Def., UK Conducts UN Sanctions Enforcement to Counter North Korea’s 

Weapons Programmes, https://www.gov.uk/government/news/uk-conducts-un-sanctions-enforcement-to-counter-north-koreas-weapons-programmes. 

xxxix Joe Brock, China's Military Drills Near Taiwan Disrupt Key Shipping Lanes, Reuters (Aug. 4, 2022), https://www.reuters.com/world/

asia-pacific/chinas-military-drills-near-taiwan-disrupt-key-shipping-lanes-2022-08-05/. 

xl China Fighter Jet Intercepts Australian Plane, BBC (Jun. 5, 2022), https://www.bbc.com/news/world-australia-61696973; Statement from the Canadian Armed Forces (Jun. 1, 2022), 

https://www.canada.ca/en/department-national-defence/news/2022/06/statement-from-the-canadian-armed-forces.html; Oren Liebermann, Chinese Fighter Jet Intercepts US Recon 

Aircraft with ‘Unsafe Maneuver,’ US Defense Department Says, CNN (Dec. 29, 2022), https://www.cnn.com/2022/12/29/politics/chinese-fighter-jet-intercepts-us-reconnaissanceaircraft/index.html. 

xli R. P. Pedrozo, China Again Uses Force to Bully Its Neighbors, Lawfare (Dec. 10, 2021), https://www.lawfareblog.com/china-again-uses-force-bully-its-neighbors; Update, China Blocks Another 

Philippine Resupply Mission, CSIS AMTI (Jul. 27, 2022), https://amti.csis.org/three-rounds-of-coercion-in-philippine-waters/. 

xlii China Escalates Coercion Against Vietnam’s Longstanding Oil and Gas Activity in the South China Sea, U.S. State Dep’t (Aug. 21, 2019), https://china.usembassy-china.org.cn/china-escalatescoercion-against-vietnams-longstanding-oil-and-gas-activity-in-the-south-china-sea/. 

xliii Shigeki Sakamoto, China’s New Coast Guard Law and Implications for Maritime Security in the East and South China Seas, Lawfare (Feb. 16, 2021), https://www.lawfareblog.com/chinasnew-coast-guard-law-and-implications-maritime-security-east-and-south-china-seas; R. P. Pedrozo, Maritime Police Law of the People’s Republic of China, 97 Int’l L. Stud. 465 (2021); Ryan D. 

Martinson, Gauging the Real Risks of China’s New Coastguard Law, Australian Strategic Policy Institute: The Strategist (Feb. 23, 2021), https://www.aspistrategist.org.au/gauging-the-real-risksof-chinas-new-coastguard-law/; A New Law Would Unshackle China’s Coastguard, Far From Its Coast, The Economist (Dec. 3, 2020), https://www.economist.com/china/2020/12/03/a-newlaw-would-unshackle-chinas-coastguard-far-from-its-coast; Nguyen Thahn Trung, How China’s Coast Guard Law Has Changed the Regional Security Structure, CSIS AMTI (Apr. 12, 2021), 

https://amti.csis.org/how-chinas-coast-guard-law-has-changed-the-regional-security-structure/. 

xliv See, e.g., U.S. State Dep’t Limits in the Seas Nos. 143 & 150, available at https://www.state.gov/limits-in-the-seas/; Award, South China Sea Arbitration (Republic of Philippines v. People’s 

Republic of China) (P.C.A. Case No. 2013-19), available at https://pcacases.com/web/sendAttach/

2086. 

xlv See, e.g., U.S. Navy NAVPLAN 2022, supra note i, at 6 (“The naval service’s ability to control the seas and project power—from both land and sea— has underpinned America’s national 

defense and economic vitality for generations. It is central to integrated deterrence in the future. Sea control provides freedom of maneuver to the Joint Force and our allies while denying it 

to our enemies in conflict. Our ability to project power deters aggression by convincing rivals they have no viable means of achieving their objectives through force.”); Tri-Service Maritime 

Strategy, supra note i. 

xlvi L. Pratso, Communications in Transportation Research, 3 Com. Transp. Res. 2-3 (2023). 

xlvii Id. at 2. Examples of chokepoints include the Panama Canal, Gibraltar Strait, English Channel, Danish Straits, Bosporus Strait, Suez Canal, Bab el Mandeb Strait, Strait of Hormuz, Malacca 

Strait, Lombok-Makassar Strait, Ombai Strait, South China Sea, and East China Sea. Id. at fig. 1.

xlviii Tri-Service Maritime Strategy, supra note i, at 21 (“In conflict, the Naval Service will establish, maintain, and exploit sea control in contested environments from the littorals to open ocean, 

including critical chokepoints.”) (emphasis added). 

xlix Id. at 13 (“In collaboration with allies and partners, we will be capable of controlling critical choke points, enabling us to safeguard joint forces flowing into theater and to impose military 

and economic costs on our adversaries.”) (emphasis added). See note xvii for the definition of contraband and war-sustaining.

l Tri-Service Maritime Strategy, supra note i, at 13.

li See note xxxvii. 

lii See, e.g., U.S. 7th Fleet, 7th Fleet Destroyer Transits Taiwan Strait (Jan. 5, 2023); Agence France-Presse, UK Sends Warship Through Taiwan Strait for First Time in More Than a Decade, The 

Guardian (Sep. 27, 2021) (“Britain sent a warship through the Taiwan strait...a move that challenges Beijing’s claim to the sensitive waterway....”).

liii Congressional Research Service, U.S.-China Strategic Competition in South and East China Seas: Background and Issues for Congress (Rpt. No. R42784) (updated Feb. 8, 2023), at 2, 116; S. 

Burgess, Confronting China’s Maritime Expansion in the South China Sea, J. Indo-Pac. Aff. (Fall 2020), at 112-30; Sec’y of State Blinken, DoS Press Statement, Fifth Anniversary of the Arbitral 

Tribunal Ruling on the South China Sea (Jul. 11, 2021) (“Nowhere is the rules-based maritime order under greater threat than in the South China Sea. The People’s Republic of China (PRC) 

continues to coerce and intimidate Southeast Asian coastal states, threatening freedom of navigation in this critical global throughway.”) (emphasis added) [hereafter SECSTATE Blinken 5th 

Anniversary Statement].

liv See, e.g., U.S. 7th Fleet, 7th Fleet Cruiser Conducts Freedom of Navigation Operation in South China Sea (Nov. 28, 2022); SECSTATE Blinken 5th Anniversary Statement, supra note liii; U.S. 

Dep’t of Def., Fact Sheet: Freedom of Navigation Program (Mar. 2015) (“Some coastal states in the world have asserted maritime claims that the United States considers to be excessive--that 

is, such claims are inconsistent with the international law of the sea and impinge upon the rights, freedoms, and uses of the sea and airspace guaranteed to all states under that body of 

international law. The United States, however, ‘will not...acquiesce in unilateral acts of other states designed to restrict the rights and freedom of the international community.’").