South China Sea Arbitration

The South China Sea Arbitration (Philippines v. China, PCA case number 2013–19) was an arbitration case brought by the Republic of the Philippines against the People's Republic of China (PRC) under Annex VII (subject to Part XV) of the United Nations Convention on the Law of the Sea (UNCLOS, ratified by the Philippines in 1984, by the PRC in 1996, opted out from Section 2 of Part XV by China in 2006) concerning certain issues in the South China Sea, including the nine-dash line introduced by the mainland-based Republic of China since as early as 1947. A tribunal of arbitrators appointed the Permanent Court of Arbitration (PCA) as the registry for the proceedings.

On 19 February 2013, China declared that it would not participate in the arbitration. On 7 December 2014, it published a white paper to elaborate its position that, among other points, the tribunal lacks jurisdiction. In accordance with Article 3 of Annex VII of UNCLOS, the Philippines appointed 1 of the 5 arbitrators, while China did not appoint any. On 29 October 2015, the tribunal concluded that it had jurisdiction to consider seven of the Philippines' submissions, subject to certain conditions, and postponed the consideration of its jurisdiction on the other eight submissions to the merits phase.

On 12 July 2016, the arbitral tribunal ruled in favor of the Philippines on most of its submissions. It clarified that while it would not "rule on any question of sovereignty ... and would not delimit any maritime boundary", China's historic rights claims over maritime areas (as opposed to land masses and territorial waters) within the "nine-dash line" have no lawful effect unless entitled to under UNCLOS. China has rejected the ruling, as has Taiwan. As of November 2023, 26 governments support the ruling, 17 issued generally positive statements noting the ruling but not called for compliance, and eight rejected it. The United Nations does not hold any position on the case or on the disputed claims.