Philippines seeks multilateral arbitration case against PRC’s South China Sea aggression

FORUM Staff
The Philippines plans a potential new arbitration case against the People’s Republic of China (PRC) for continued violations of international law in the South China Sea, and Manila hopes other nations join a multilateral legal case, officials say.
The Philippines wants to file a “foolproof, solid case,” Andres Centino, chief presidential advisor on maritime affairs, told the Financial Times newspaper in mid-December 2024.
VIDEO CREDIT: PHILIPPINE COAST GUARD
Manila successfully pursued a previous case against the PRC for violating the United Nations Convention on the Law of the Sea (UNCLOS). Beijing refused to participate in the arbitration and has ignored the international tribunal’s 2016 ruling that invalidated its sovereignty assertions. The PRC claims nearly all of the South China Sea despite overlapping claims from Brunei, Indonesia, Malaysia, the Philippines and Vietnam.
The Philippines is seeking support from UNCLOS signatories to “stand up against China on behalf of everyone,” Centino told the newspaper.
A unified legal action by multiple nations could increase enforcement of a future ruling against the PRC, Centino said: “If they were dealing with a lot of countries, maybe that would be more forceful.”
UNCLOS, which took effect in 1994, has been ratified by 170 parties, including the PRC. Among other measures, it established 200-nautical mile exclusive economic zones (EEZ) in which coastal countries have the right to manage and benefit from the natural resources within their zones.
The PRC routinely ignores other nations’ EEZ boundaries. To impose its illegal claim at Second Thomas Shoal and surrounding areas, China Coast Guard vessels have rammed, obstructed and fired water cannons at Philippine resupply boats. The PRC also harasses civilian fishing crews in Philippine waters, interferes with Indonesian, Malaysian and Vietnamese vessels, and obstructs oil and gas operations in those nations’ waters. In January 2025, the China Coast Guard’s largest vessel patrolled within the Philippine EEZ in what Manila labeled an illegal act of “intimidation, coercion, aggression and deception” to bully Philippine fishing vessels.
“Will this lead to another case?” Jonathan Malaya, assistant director-general of the Philippines’ National Security Council, said in mid-January. “All options are on the table because the closer the [Chinese Communist Party] monster ship is in Philippine waters, the more it makes tensions high and the more that the Philippine government contemplates things it was not contemplating before.”
Tensions also flared in June 2024 when China Coast Guard boats rammed and boarded Philippine Navy vessels attempting to resupply the Sierra Madre, the ship serving as a Philippine military outpost at Second Thomas Shoal. The confrontation severely injured a Philippine Sailor and damaged Philippine boats. Videos of China Coast Guard personnel wielding axes sparked international outrage and condemnation. Afterward, the two nations negotiated a provisional agreement under which Manila has conducted undisrupted resupply missions to the shoal.
A new claim against the PRC under UNCLOS arbitration procedures could include an environmental case based on destroyed resources. The Philippines previously called for an international inquiry into environmental damage at a South China Sea shoal, including a massive loss of giant clams. In mid-2024, the Philippine Coast Guard released surveillance photographs of Chinese fishermen harvesting giant clams in a lagoon at Scarborough Shoal. It said such activity occurred for years. Surrounding coral appeared badly scarred by what the Philippines characterized as a futile search for more clams.
Claims also could focus on the PRC’s use of force to harass Philippine and other nations’ vessels in the South China Sea, and the violation of the Philippines’ sovereign rights by PRC interference with resupply missions to Second Thomas Shoal and the disruption of fishing within the Philippines’ EEZ.
Philippine Solicitor General Menardo Guevarra said in September 2024 that the nation was considering a second UNCLOS case before the Permanent Court of Arbitration, according to the Reuters news agency. Guevarra said the case likely would focus on PRC environmental damage to Iroquois Reef in the Spratly Islands — a group of reefs, shoals and atolls about halfway between the Philippines and Vietnam, which are claimed by several countries.
Antonio Carpio, a former Philippines Supreme Court associate justice, also recommended a new claim in September 2024, saying it could be based on damage to Philippine Coast Guard vessels during the June 2024 encounter.
Pursuing the claim could slow PRC aggression, he said, because the international tribunal criticized Beijing for aggravating the dispute during the previous proceedings.
“We should use that avenue to deter China,” Carpio told the ANC news channel. “We should ask allies to help us.”