The “Freedom of Navigation” Claimed by the United States is Not “Freedom of Navigation” under International Law

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2023-06-03 | Lei Xiaolu

“Freedom of navigation” is a core claim of the U.S. maritime order and has been used to accuse and suppress China's maritime activities. Recently, the U.S. Embassy to China published an article on the U.S. position on the history and connotation of “FON” as a standard to the principle of “freedom of navigation” in international law. In fact, the “FON” pursued by the United States and the “FON” recognized by international law are not the same thing at all.


The right of navigation and its limitations under the United Nations Convention on the Law of the Sea and general international law


There is a fundamental difference between the freedom of navigation claimed by the United States and the real freedom of navigation under international law. According to the U.S. Embassy article, freedom of navigation is the right of its ships and aircraft to navigate and overfly in so-called “international waters” and innocent passage in the territorial waters of coastal states “without unlawful restrictions by States.”[1] According to the U.S. Department of Defense report, freedom of the seas means not only freedom of passage for merchant ships, but also the use of air and sea by military vessels and aircraft.[2]

Although the concept of “freedom of the seas” has an ancient history, the rules of international law governing navigation have changed significantly with the development of the international law of the sea, particularly with the conclusion of the United Nations Convention on the Law of the Sea (hereinafter referred to as “the Convention”). Despite the best efforts of the United States to unite with its allies in negotiations to maintain the so-called freedom of navigation in traditional ways, the Convention ultimately aims to maintain a balance between the interests of maritime powers and coastal states. There has never been an unrestricted right of navigation in the Convention or in general international law.

The disagreement between the United States and China is not about whether other states have navigational rights in the various maritime areas, but rather about the extent to which navigational and other rights can be enjoyed and exercised, specifically, what constitutes an “unlawful restriction” on the navigational rights of coastal states.

U.S. national and military strategy requires that its warships, aircraft, and submarines have unimpeded passage through the world's vital seas, straits, archipelagic sea lanes, and the territorial and archipelagic waters of archipelagic states, more precisely,  “it is in the best interests of both coastal and maritime States that the coastal state not be faced with a decision as to whether or not to permit transits”.[3] In 1986, when U.S. aircraft passed through the Strait of Gibraltar for military operations against Libya, neither Spain nor Morocco, as coastal states, were asked for consent for U.S. aircraft to fly over their territorial waters within the Strait. Thus, what the United States insisted upon and pursued was a right of unimpeded transit passage without the consent, or any reaction from the coastal states.



This position, is clearly not fully supported by the Convention. Although foreign ships enjoy the right of innocent passage in the territorial sea, Article 25 of the Convention provides that the coastal state may take the necessary steps to prevent passage which is not innocent. That is, the coastal States have the right to decide whether the passage of a foreign ship is consistent with the “right of innocent passage” under Article 19. The Convention also provides that the coastal State may adopt domestic law on innocent passage and may require a foreign warship that disregards any request for compliance with domestic law to leave the territorial sea immediately.[4] The Convention does not specify what steps and measures a coastal state may take or how a coastal state may “require” a foreign warship to leave its territorial seas. The practice varies from State to State. There is clearly no right of navigation in the territorial seas of a coastal state that ignores its decisions. U.S. warships may exercise the right of innocent passage, but at the same time must respect the coastal state's determination of whether the passage is innocent and comply with the laws and regulations of the coastal State concerning passage through the territorial sea.

The right of navigation is not unrestricted in waters beyond the territorial sea. The United States argues that the freedom of navigation of the high seas is applicable beyond the territorial sea, and thus created the concept of “international waters”, which seems to express a meaning similar to the concept of “international airspace” in international law. However, unlike international law concerning airspace, the Convention categorized the ocean into different maritime zones, such as internal waters, territorial sea, contiguous zone, exclusive economic zone, continental shelf, high seas and the Area, and the rights and obligations of states varies.

The United States upholds that the exclusive economic zone (hereinafter referred to as “EEZ”), and the continental shelf only entitles the coastal state sovereign rights and jurisdiction related to the use of natural resources. In practice, however, the exercise of navigational rights in the EEZ should also take the obligation of “due regard” under Article 58 into account. Article 58 does not specify which kind of interests need to be “due regard”. During the negotiation of the Convention, the issue of the limits and legality of military activities in the EEZ was discussed, and concerns regarding the security interests of coastal States were raised by Peru, Brazil, Uruguay and others.[5] Until now, there is no consistent state practice among states on this issue. But at least, the right of navigation in the EEZ is limited by the jurisdiction of the coastal state regarding natural resources and marine environmental protection.

The Convention also provides the regime of the straits used for international navigation and archipelagic sea lanes. All these regimes reflect the delicate balance between the sovereignty, sovereign rights and jurisdiction of the coastal State and the interests of navigation of other States. On the one hand, it guarantees the right of navigation, and on the other, it maintains the space for coastal states to take measures to safeguard their national security. Although President Reagan stated in 1983 that the United States “prepared to accept and act in accordance with the balance of interests relating to traditional uses of the oceans—such as navigation and overflight”,[6] the balance of interests as understood by the United States may differ from the understanding of state parties to the Convention.

The United States is not a party to the Convention. In accordance with Articles 31 and 32 of the Vienna Convention on the Law of Treaties, subsequent practice of the parties is to be considered when interpreting the Convention. That is, the Convention is likely to evolve in accordance with the subsequent practice of the Parties. But as a non-party to the Convention, the practice of the United States means nothing for the interpretation of the Convention. The United States has repeatedly asserted that the Convention reflects customary international law in the 1980s, but if the customary international law develops with different state practice, it might be inconsistent with the living Convention.

Therefore, if the United States wants to preserve its navigational interests, forcing its position through unilateral acts is not the best option. It must face up to and respect the space reserved by the Convention for coastal States to maintain their national security and resolve the relevant issues with the States concerned through bilateral or multilateral legal arrangements.


U.S. “Freedom of Navigation Operations”


In 1979, noting that the forthcoming Convention would lead to creeping jurisdiction, and in response to what it called “excessive maritime claims,” the Carter Administration decided to implement the “Freedom of Navigation Program”.[7] The U.S. scholar William Aceves has pointed out that the FON program was established to warn countries that the United States would not tolerate claims having an adverse impact on maritime transit.[8]

The United States has repeatedly touted its so-called freedom of navigation as a means of securing sea lanes and commercial prosperity, but this is not the case. According to the U.S. Department of Defense's 2015 Asia-Pacific Maritime Security Strategy report, when it uses freedom of the seas, it means not only freedom of passage for merchant ships, but also the use of air and sea by warships and aircraft. The U.S. Department of Defense elaborates on the reasons for implementing the “FON program” in the Asia-Pacific, noting that “EEZs in the USPACOM region constitute 38 percent of the world’s oceans” and “if these excessive maritime claims were left unchallenged, they could restrict the ability of the United States and other countries to conduct routine military operations or exercises in more than one-third of the world’s oceans.”[9]

Thus, while the U.S. “FON program” may be intended not to deter coastal states but to declare its legal position, the criteria of the implementation has largely relied on whether the claim affects freedom of navigation of the United States. This also determines that it is unlikely for the US to recognize the ambiguity of international law on this issue and take the initiative to solve the problem in an equal and consultative manner, taking into account the concerns and interests of other countries.

For more than 40 years, the United States has claimed that it conducts its “FON program” against unspecified countries, seemingly emphasizing the neutrality of the operation. Since 2007, China has been a target country for the U.S. “FON program”. According to information publicly released by the Congressional Research Service and the U.S. Seventh Fleet, from 2015-2022, a total of 39 “FON operations”, or FONOPS, have been conducted against China around the islands and reefs in the South China Sea.[10]


More importantly, unlike other “FONOPS”, U.S. “FONOPS” near islands and reefs in the South China Sea are more politically and strategically provocative.

The United States does not usually release details of its “FON program”, but since 2015, the U.S. has taken the initiative to disclose the vessels and details of its “FONOPS” in response to the legal status of the islands and reefs in the South China Sea. Almost every operation is closely aligned with important U.S. policies and issues related to the sea and China. According to scholarly statistics, of the 39 “FONOPS” in the South China Sea from 2015 to 2022, at least 22 were related to U.S. China-related and maritime-related policy trends, mainly involving the construction of the Nansha islands and reefs, the South China Sea arbitration case, and the consultations for a “Code of Conduct for the South China Sea”.[11]

It can be seen that the U.S. “FONOPS” have nothing to do with maintaining the safety of international waterways and the prosperity of maritime trade, as they are touted, but are akin to military activities to advance U.S. global strategy and safeguard U.S. security interests. It has nothing to do with international law, and is actually a domestic system design and practice created by the United States outside the Convention mechanism.


The Rules-based Maritime Order as Unilateral U.S. Hegemonic Tools


The U.S. has repeatedly explained the historical and practical roots of its unwavering defense of freedom of navigation, and in fact this logic has been very clearly shown to the world: the U.S. national interests depend on a liberal international order, and therefore it will spare no effort to promote this international order, including the so-called freedom of navigation. The United States sees this as a common interest of the world, seeking to establish and maintain a “rules-based maritime order” with like-minded countries.

The United States seems particularly puzzled that such a wonderful idea could be questioned, since it has never cared about or even deliberately ignored the interests and views of other countries. In fact, the negotiation process at UNCLOS III has made it clear that absolute freedom of the seas will provide a wide space for maritime powers to realize their interests, while other nations will face national security threats. It is difficult to imagine how a country can have the confidence to designate archipelagic sea lanes in an open posture when it does not have the ability to sense the passage of nuclear submarines through its archipelagic waters, or how a country can have the confidence to minimize restrictions on the navigation of warships of other countries in an open posture when it does not have sufficient defense capabilities.

When differences arise, the United States does not tend to seek a lasting and peaceful solution through bilateral or multilateral channels with the countries concerned on the basis of sovereign equality and mutual understanding, but withdraws from international mechanisms when it believes that its national interests cannot be fully reflected, and to defend its national interests in a unilateralist manner with its power. The “FON program” is a perfect example: it is based on a unilateral U.S. interpretation of the international law of the sea, and through this unilateralist act, it prevents the formation of international law that is not favorable to U.S. interests, imposes its claims and positions on other countries, and promotes a “rules-based maritime order” that prioritizes U.S. interests.

The international order should not be based solely on the national interests of any single country, or following the standards of a few countries, but rather on the common interests of all countries. The international order based on international law provides a strong mechanism for safeguarding the common interests of all countries. Only by adhering to the multilateralism mechanism with the United Nations as the core, and the rules of international law, can we truly maintain lasting peace, prosperity and stability of the world. If the U.S. “FON” and “rules-based maritime order” have similar connotations, or if it really wants its position to be understood and accepted, it should seriously consider the positions and concerns of other countries on the right of navigation on an equal footing, and solve problems through bilateral and multilateral arrangements, instead of demanding other States to act according to its standards and interpretations in an imperious tone.



[1] 美国驻华大使馆:《“航行自由”的前世今生》,,2023年5月12日访问。
[2]Department of Defense of US, Asia-Pacific Maritime Security Strategy: Achieving U.S. National Security Objectives in a Changing Environment, 2015.
[3]Dennis Mandsager, The US Freedom of Navigation Programme: Policy, Procedure, and Future, in Michael N. Schmitt (ed.), The Law of Military Operations: Liber Amicorum Professor Jack Grunawalt, (International Law Studies Volume 72) (Newport, RI: Naval War College Press, 1998), p. 113–127. 
[5]Commentary, Art.58, pp. 553-565.
[6]U.S. Department of Defense, “Freedom of Navigation Program: Fact sheet”, March 2015, p 1,
[7]See Anisa Heritage and Pak K. Lee, Order, Contestation and Ontological Security-Seeking in the South China Sea, Palgrave Macmillan, 2020, p.118; William J. Aceves, “The Freedom of Navigation Program: A Study of the Relationship between Law and Politics,” Hastings International and Comparative Law Review, vol. 19, no. 2 (1996), pp.259–326.
[8]William J. Aceves, “The Freedom of Navigation Program: A Study of the Relationship between Law and Politics,” Hastings International and Comparative Law Review, vol. 19, no. 2 (1996), pp.259–326.
[9]Department of Defense, The Asia-Pacific Maritime Security Strategy: Achieving U.S. National Security Objectives in a Changing Environment, 2015, p.24.
[10]Congressional Research Service, US-China Strategic Competition in South and East China Seas: Background and Issues for Congress, updated February 8, 2023.


Lei Xiaolu

Lei Xiaolu, is currently a professor in China Institute of Boundary and Ocean Studies (CIBOS), Wuhan University, and vice director of SCSPI. She obtained her LLM degree in 2009 and PhD Degree in 2012 from Wuhan University specialized in international law. In 2017, she was a visiting scholar at S. Rajaratnam School of International Studies (RSIS), Nanyang Technology University of Singapore. Her research interest covers the area of pacific dispute settlement mechanisms, especially the peaceful settlement of the South China Sea disputes, China’s maritime law and policy, and the legal issues in the law of the sea and general international law.