Report to Congress on South China Sea Disputes

The following is the Aug. 25, 2026, Congressional Research Service report, China Primer: South China Sea Disputes.

From the Report

Multiple Asian governments assert sovereignty over rocks, reefs, and other geographic features in the heavily trafficked South China Sea (SCS), with the People’s Republic of China (PRC or China) arguably making the most assertive claims. While United States makes no territorial claim in the SCS and takes no position on sovereignty over any of the geographic features in the SCS, U.S. officials have long urged that disputes be settled without coercion and on the basis of international law. Separate from the sovereignty disputes, the governments of the United States, China, and other countries disagree over what rights international law grants foreign militaries to fly, sail, and operate in a country’s territorial sea or exclusive economic zone (EEZ). For more than a decade, some Members have examined China’s efforts to use coercion and intimidation to increase its control over the SCS and have passed legislation aimed at improving the ability of the United States and its partners to protect their interests.

An estimated one-fifth to one-third of global ship-borne commerce transits the SCS each year, and U.S. allies and partners like Japan, the Philippines, South Korea, and Taiwan are dependent on its waterways for trade. According to estimates cited by the U.S. Energy Information Administration, the SCS contains “proved” or “probable” reserves of approximately 3.6 billion barrels of oil and 40.3 trillion cubic feet of natural gas. The SCS has significant fish stocks, coral, and other undersea resources.

The PRC and the other SCS claimants (except Taiwan, which is not a member of the United Nations) are parties to the 1994 UN Convention on the Law of the Sea (UNCLOS). The United States is not a party but has long had a policy of abiding by UNCLOS provisions relating to territorial waters, EEZs, and navigational rights. UNCLOS allows state parties to claim 12-nautical mile (nm) territorial seas and 200-nm EEZs around their coastlines and “naturally formed” land features that can “sustain human habitation.” Naturally formed land features that remain above water at high tide, but which are not habitable, are entitled to territorial seas, but they are not entitled to EEZs.

Download the document here.