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Law of the Sea Treaty: Context, Role, and Limitations in the South China Sea

Post Authored By: Ted S. Kontopoulos

Historically, various legal grounds justified powerful nations asserting sovereignty claims over strategically located maritime territories at the expense of weaker nations. These claims consolidated a nation’s geopolitical influence, secured existing or new trade routes, and reinforced their borders.  Today, those same national interests are driving the most intense competition for maritime sovereignty claims in and around the East Sea, commonly known as the South China Sea.  Claims are increasingly competitive there because the South China Sea contains over 10,000 species of fish, accounts for one-third of the world’s seafood exports, and impacts nearly two-thirds of Asia-bound maritime trade routes.


From the 1600s until 1958, disputes between nations claiming sovereignty over the same maritime territory were primarily resolved through military force or settled under customary international law. Unlike a treaty, customary international law referred to general concepts that nations observed as law despite not being formally written down. As an example, consider the freedom of the seas concept. Under this concept’s “cannon shot” rule, a nation received sovereign rights to a specified area – typically extending 3 nautical miles (5.6 km; 3.5 mi) – from its coastline. The cannon shot rule was widely observed and accepted by nations until the early to mid-20th century.

In 1956, the United Nations held its first Conference on the Law of the Sea (“UNCLOS I”). Among other things, UNCLOS I developed a commonly accepted framework for resolving maritime legal disputes. Ultimately, UNCLOS I resulted in four treaties concluded in 1958.

In 1982, after decades of negotiations, the Law of the Sea Treaty (“LOST”) replaced the four treaties concluded under UNCLOS I. LOST established an even broader legal framework for resolving disputes over maritime and marine activity. As of this article’s publication date, 168 nations have ratified LOST as parties. Notably, parties to LOST include the European Union, China and the Philippines, but exclude the United States.


Although LOST establishes a broad legal framework covering most maritime disputes, some disputes remain outside the treaty’s jurisdiction and ability to resolve. For instance, if two nations claim sovereignty over the same maritime territory, then that dispute falls outside LOST’s jurisdiction and must be resolved through other peaceful means. If a dispute falls outside LOST’s jurisdiction, then a party to the treaty may refuse both to participate in the arbitration process and to recognize the results. In contrast, if a dispute falls inside LOST’s jurisdiction, then a tribunal of arbitrators is convened, each side presents legal arguments, and the tribunal decides the outcome by first applying the treaty’s rules then secondarily applying customary international law. 

The Philippines-China Case in the South China Sea

In 2013, several disputes in the South China Sea prompted the Philippines to initiate arbitration proceedings against China under LOST. From Manila’s perspective, the disputes concerned the legal basis of South China Sea maritime rights, the status of certain geographic features, and the lawfulness of certain actions taken by China. This perspective argued that the disputes fell within LOST’s jurisdiction, had to be resolved through arbitration proceedings, and the tribunal properly exercised its powers to decide the results.

China countered that the proceedings lacked jurisdiction under LOST. From Beijing’s perspective, the disputes arose from the two countries claiming sovereignty over the same maritime territories in the South China Sea. This perspective argued that the disputes fell outside LOST’s jurisdiction, pressed for a resolution through other peaceful bilateral means, and justified both China’s refusal to participate in the arbitration proceedings as well as its refusal to recognize the results.

In July 2016, the LOST tribunal published the arbitration’s results. In January 2019, I published a note in the University of Illinois Law Review explaining the results, forecasting the consequences, and suggesting some solutions from bilateral and multilateral perspectives [insert hyperlink:].  Overall, the arbitration has produced legal ambiguity and accelerated pre-existing geopolitical trends in the region.

Today, economic, political, and military pressures compel some nations to side with the Philippines, other nations to side with China, and some to remain neutral. Unfortunately, historical problems also persist for peacefully resolving disputes from overlapping sovereignty claims to maritime territory in the strategically-located South China Sea.  Hopefully, LOST and bilateral diplomacy mechanisms resolve or mitigate these disputes before they spiral out of control into military conflicts.

About the Author:

Ted earned his J.D. magna cum laude from the University of Illinois Chicago College of Law, served as an editor on law review, and won a 2018 Rickert Award for excellence in legal writing for his article titled “Fish, Friends, and Flashpoints in South China Sea.” He earned his B.A. magna cum laude from Boston College, graduated Phi Beta Kappa with highest honors in the political science department, and served as an apprentice in the U.K. House of Lords for Earl John Attlee. Ted currently serves as the co-chair on the YLS Federal Taxation Committee and as co-editor-in-chief of the YLS Journal. He has published articles in Tax Notes, Journal of Multistate Taxation and Incentives, the CBA Record, Journal of International Taxation, and the University of Illinois Law Review.

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