
The early April passage of the French frigate Vendémiaire through the Taiwan Strait, amid a significant increase of such passages by U.S. warships despite China’s objections, gives Beijing one more reason to consider withdrawing from the UN Convention on the Law of the Sea (UNCLOS) altogether. Withdrawing would have serious costs as well as benefits and both need to be considered.

The idea of withdrawing from UNCLOS (“denouncing it” in legal parlance) has come up before, particularly in regard to China’s nine-dash line historic claim to much of the South China Sea and an international arbitration panel’s ruling against it as not in keeping with UNCLOS. China refused to recognize or abide by the result. This in turn damaged China’s international standing and stirred a domestic nationalist reaction that worried the Chinese leadership. At the time, some of China’s analysts and military officers quietly questioned why China ratified the Law of the Sea Treaty in the first place. Part of the explanation is that China assumed — obviously incorrectly — that it could avoid the UNCLOS dispute settlement mechanism by its optional exceptions to the compulsory procedures, and through direct negotiations to settle maritime jurisdictional disputes.

The historic claim issue was primarily driven by and had ramifications for national pride and domestic political concerns rather than direct security concerns. But now China is facing what its military perceives to be clear and present dangers to its security in — and from — its vulnerable maritime underbelly, the South China Sea. A prime example are the increasingly provocative Freedom of Navigation Operations (FONOPs) that the United States uses to challenge China’s claims in the South China Sea. The China-U.S. differences over FONOPs are more political and strategic than legal. Nevertheless, the United States characterizes the dispute as “legal” and insists that China is in the wrong. Washington maintains that it is simply exercising its “right” to “fly, sail and operate wherever international law allows,” including the right of its warships to sail in innocent passage through foreign territorial seas without prior permission. China and several other nations in Asia, like Indonesia and Vietnam, require permission for foreign warships to enter their territorial seas. Even more egregious from the U.S. perspective, India, Malaysia, and U.S. ally Thailand do not allow foreign military activities in their exclusive economic zones (EEZs) without permission.

China alleges that these FONOPs are a threat to its sovereignty, integrity and security. Its legal reasoning is not clear. Perhaps it views FONOPs as a threat of use of force, which is a violation of the UN Charter and cross-referenced in UNCLOS. For China, the threat to its security should be sufficient reason for the United States to cease and desist. Whatever the reason, there is obviously disagreement as to the interpretation of the relevant international law and who is violating it.

Now — amidst increasing tension between China and the United States across the board — the stepped-up U.S. warship passages, as well as that of the Vendémiaire, through the Taiwan Strait have come to the fore as both a political and security issue. Given recent advances in military weaponry and intelligence collection technology and techniques, China’s military probably thinks that the United States — and now France and soon maybe the United Kingdom and Japan — are or will be taking advantage of what China sees as a loophole in the Law of the Sea to threaten its security and embarrass its leaders, both at home and abroad.

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UNCLOS qualifies the right of transit passage through straits by stating that “if the strait is formed by an island of a State bordering the strait and its mainland, transit passage shall not apply if there exists seaward of the island a route through the high seas or through an EEZ of similar convenience.” In Beijing’s interpretation of the One China policy, all the waters in the Taiwan Strait are under China’s jurisdiction and comprise its internal waters, territorial seas, and EEZ. Thus Beijing apparently claims that according to this UNCLOS provision, the right of transit passage does not apply to the Taiwan Strait — warships in particular should use the alternative route “of similar convenience” through the Luzon Strait between the island of Taiwan and the Philippines. The United States, however, claims high seas freedom of navigation and overflight for all vessels and aircraft, including military vessels and aircraft, through the Strait regardless of whether it is Beijing’s EEZ or Taiwan’s EEZ. To Washington, such freedom of navigation and overflight includes related activities such as anchoring; launching and recovery of aircraft and water craft or other military devices; intelligence, surveillance and reconnaissance activities; exercises; maneuvers; and “military surveys.” China presumably sees such activities in the Taiwan Strait as a threat to its security.

International politics also played a major role in China’s reaction to the Vendémiaire passage. In September 2018, presumably at the instigation of the United States, the U.K. conducted a FONOP near the Paracels. France’s Taiwan Strait passage — perhaps also at the urging of the U.S. — demonstrated that extraregional powers are coming to the political assistance of the United States against China on this issue and Beijing has thus decided to impose political costs as a warning to them and others.

Clearly, China considers the West’s interpretation of some key aspects of the UN Convention on the Law of the Sea as benefiting the West to its disadvantage. China and other developing countries view the Treaty as a package deal with many “bargains” between the maritime powers and the developing countries, including extensive navigational rights for maritime powers in exchange for the deep seabed mining provisions. Although some 167 parties, including U.S. allies have ratified the Treaty, the United States has not done so. In China’s view, Washington is now picking and choosing interpretations of provisions that favor it to the detriment of China’s security. This — combined with the increasing forceful assertions by the United States and others of their interpretations — might lead China to re-evaluate remaining a party to the Treaty.


There would be serious political costs for withdrawing from UNCLOS. It would result in a wave of international opprobrium and a propaganda coup for anti-China factions in the West and Asia. It would also create fear and even instability in the region and probably draw some Asian states closer to the United States as a “balancer” to China.

However there would also be advantages to such an action. China would then be legally free to “pick and choose” the Convention’s provisions and interpret them in its favor — just as the United States does now. China’s withdrawal from the Convention would weaken it and the authority of its dispute settlement mechanism. China may welcome that as Beijing — like rising powers before it — seeks to alter the interpretation of international law in its favor. At the least, it would give notice that China is not to be trifled with.

The United States and its Asian allies need to be careful lest they push China into actually being what many fear most — another rogue country that successfully engages in coercion in its international relations. Indeed, the proliferation and growing security threats of these disagreements may eventually lead China to consider the costs of withdrawing from the Treaty less than the benefits.

Mark J. Valencia is Adjunct Senior Scholar at the National Institute for South China Sea Studies, Haikou, China.