An arbitration court accepted claims made by the Philippines against China in the South China Sea, however, China’s refusal to obey the court’s decision requires a swift, but measured response from the United States.

On Tuesday, the Permanent Court of Arbitration based in The Hague, Netherlands, handed down its final decision in The Republic of Philippines v. The People’s Republic of China, the case concerning ongoing maritime disputes in the South China Sea. As expected, the arbitration court ruled largely in favor of the claims made by the Philippines. Also, as expected, China reiterated that it has no intention of respecting the arbitration court’s decision in any way.

Against this backdrop there are some who maintain that U.S. accession to the U.N. Convention on the Law of the Sea is somehow pivotal to the resolution to these disputes and the arbitration. The rationales given for that position vary. Some claim that U.S. accession would bolster “Washington’s sincerity about upholding international norms”; others maintain that U.S. membership would dispel “the perception that [the U.S.] only abides by international conventions when doing so aligns with its national interests.”

Proponents of U.S. accession also claim that the U.S. cannot fully protect its maritime interests in the South China Sea and around the globe unless it joins the U.N. Convention on the Law of the Sea. Indeed, proponents of that U.N. agreement believe U.S. membership in the treaty would be determinative in any number of maritime controversies, including Chinese aggression in the South China Sea. Yet China will not be swayed by U.S. accession to a treaty that China regularly violates or simply ignores.

U.S. accession to the Law of the Sea agreement will neither sway China nor guarantee U.S. navigational rights in the South China Sea. Those navigational rights are advanced, not by membership in a treaty, but by:

  • Maintaining a strong Navy;
  • Conducting persistent naval operations against China’s excessive maritime claims;
  • Supporting key U.S. allies, including the Philippines; and
  • Adhering to long-standing principles of the customary international law of the sea.

The customary international law of the sea—which includes the principles of high seas freedoms, “innocent passage” through territorial waters, and passage rights through international straits and archipelagoes—existed long before the U.N. agreement was adopted in 1982. The convention merely codified and elaborated upon these widely-accepted principles. While not a party to the U.N. treaty, the U.S.—unlike China—actually honors the convention’s provisions. The U.S. demarcates its legitimate maritime boundaries, respects the rights of coastal states within their territorial seas, and adheres to the maritime regimes regarding the 24-nautical mile contiguous zone and the 200-nautical mile exclusive economic zone.

Nothing suggests that China—or any other nation, for that matter—would respect its obligations under the U.N. agreement to a greater extent if the U.S. became a party to the convention. Moreover, accession to Law of the Sea treaty does nothing to enhance U.S. military capability. The U.S. Freedom of Navigation Program, the primary means of the U.S. confronting China’s excessive claims, does not rely on U.S. membership in the treaty.

Finally, U.S. accession to the U.N. agreement does not guarantee any kind of persuasion, coercion, or facilitation of Chinese acceptance of the arbitrations court’s decision in the Philippines v. China case. China has insisted from the beginning of the legal proceedings that it does not recognize the court’s jurisdiction over the case and will not abide by any decision handed down by the tribunal.

The U.S. should state its support for the arbitration court’s decision as reflecting its understanding of the law of the sea while continuing to protect its rights and interests in the South China Sea.

To that end, the U.S. should:

  1. Underscore U.S. policy on military activities in the South China Sea. The legality of military activities in the South China Sea, including military survey and intelligence gathering, is a major sticking point between the U.S. and China. A legal memorandum emphasizing the U.S. position on its navigational rights in the South China Sea would help to further clarify the matter. 

In addition to reiterating long-standing U.S. priorities in the SCS (i.e., respect for international law, freedom of the seas, maintenance of security and stability, and unimpeded commerce and economic development), the U.S. should delineate its case regarding the legality of military survey activities in the exclusive economic zone.


  1. Continue freedom-of-navigation protests and naval operations. The U.S. has repeatedly issued diplomatic protests (in 2001, 2002, and 2007) to China regarding its policy on restricting military surveys within its exclusive economic zone. The U.S. Navy has also conducted regular operational assertions (in fiscal years 2007–2012) to protest China’s policy. These protests must, at a minimum, continue apace. Yet more frequent naval assertions—such as those conducted recently at Subi Reef and the Paracel Islands—would signal that the U.S. is elevating the issue beyond “business as usual” in the South China Sea.

Optimally, the U.S. should conduct such operations with one or more allies in the region, such as Australia and Japan, that have the naval capabilities to participate. Vietnam and the Philippines, whose fishing and commercial survey activities have been repeatedly interfered with by China, may also be willing to engage in joint operations.


  1. Assist South China Sea nations in complying with the law of the sea. The U.S. needs to convince its friends and allies in the region to bring their domestic law and practice into compliance with the law of the sea. Several South China Sea nations (other than China) have made excessive maritime claims, including claims restricting access to their territorial sea and the exercise of military activities in their exclusive economic zones. Such claims permit China to take the position that it is acting in the same manner as its neighbors. The U.S., through bilateral negotiations, should work with South China Sea nations to abandon their excessive claims and thereby present a united legal front to China. U.S. assistance to these nations to resolve any outstanding maritime boundary issues would also be helpful.

Steven Groves is Bernard and Barbara Lomas Senior Research Fellow in the Margaret Thatcher Center for Freedom, of the Kathryn and Shelby Cullom Davis Institute for National Security and Foreign Policy, at The Heritage Foundation.