Vietnam joins Philippines in continental shelf claim, challenging PRC assertiveness in South China Sea

Maria T. Reyes

Vietnam filed a claim with the United Nations in mid-July 2024 to extend its continental shelf in the South China Sea, a month after the Philippines made a similar move in the face of the People’s Republic of China’s (PRC) increasing assertiveness in the strategic waterway.

Vietnam’s Foreign Ministry said the nation has “fully legal and scientific bases to assert that it is entitled to a continental shelf extending beyond 200 nautical miles from the baselines from which the breadth of the territorial sea is measured.” Hanoi refers to the waters as the East Sea.

According to the U.N. Convention on the Law of the Sea (UNCLOS), a coastal state’s continental shelf “comprises the seabed and subsoil of the submarine areas that extend beyond its territorial sea throughout the natural prolongation of its land territory to the outer edge of the continental margin.” UNCLOS grants states exclusive rights to explore and exploit maritime resources, such as fisheries and oil and gas deposits, within their continental shelf, which can’t exceed 350 nautical miles (about 650 kilometers) and incorporates the state’s 200-nautical-mile exclusive economic zone (EEZ).

In its submission to the U.N., the Philippines seeks to “establish the outer limits of its continental shelf” up to 350 nautical miles off the western island of Palawan.

The PRC claims almost the entire South China Sea, ignoring an international tribunal’s 2016 ruling dismissing the territorial assertions as legally invalid. Chinese coast guard and maritime militia vessels continue to block and harass vessels of other claimant states, including Malaysia, the Philippines and Vietnam, operating lawfully within their respective nation’s EEZ.

The PRC also has constructed and militarized artificial maritime features to push its territorial claims in the global trade route.

“Vietnam has gained more respect and admiration from like-minded nations on how to resolve the [South China Sea] conundrum amicably,” Chester Cabalza, president of the Manila-based think tank International Development and Security Cooperation, told FORUM. “The greatest lesson that Vietnam is imparting to the region brings forth that China does not own alone the South China Sea and the contested waters are open for all to foster a free and prosperous Indo-Pacific.”

In response to Vietnam’s submission, the Philippines said it is ready to engage with Hanoi on achieving a mutually beneficial solution to South China Sea issues, in accordance with international law. Vietnam responded similarly when the Philippines filed its claim.

By “drawing on the relevance of joint legal actions on the [extended continental shelf] of their maritime domains,” Manila and Hanoi are highlighting the value of a rules-based order, Cabalza said.

That could prompt other Association of Southeast Asian Nations members to develop a unified approach “to elevate the importance of international cooperation to maintain peace and prosperity in the tense region,” he said.

Cabalza said the submissions by Hanoi and Manila could help resolve overlapping claims in the South China Sea and “become the basis for a possible code of conduct that many claimant-countries … are wanting to forge and enforce.”

Maria T. Reyes is a FORUM contributor reporting from Manila, Philippines.