About 200 Filipinos aboard five commercial fishing vessels set sail on Wednesday towards China's Huangyan Island in the South China Sea, an area over which China has indisputable sovereignty along with its adjacent waters.

The expedition was organized by a group known as Atin Ito (This is Ours), occurring approximately two weeks after the China Coast Guard took action to expel a Philippine Coast Guard vessel and another official vessel that had entered the waters surrounding Huangyan Island without authorization.

The incident once again brought the maritime disputes between China and the Philippines in the South China Sea into the spotlight. At the crux of the disputes is Manila's illegal occupation of Ren'ai Jiao, an uninhabited reef that is an integral part of China's Nansha Qundao in the South China Sea.

On May 9, 1999, two days after the US bombing of the Chinese embassy in Belgrade, the Philippines deliberately ran aground a warship, BRP Sierra Madre, on Ren'ai Jiao. Since then, Manila has stationed a contingent of more than a dozen Philippine Marines and sailors on the dilapidated vessel, in a bid to permanently occupy the maritime feature and turn it into a military outpost.

The presence of the Philippine ship prompted immediate and serious representations from China. In response, the then Philippine president Joseph Estrada vowed to tow away the ship, saying it ran aground the reef due to "malfunction". Later, Estrada's successor, Gloria Macapagal Arroyo also pledged to remove the vessel from Ren'ai Jiao and not to "construct (new) facilities" there. But neither Estrada nor Arroyo kept their promise, nor did the later Philippine administrations.

China has patiently negotiated with the Philippines to peacefully settle the maritime disputes, including the Ren'ai Jiao issue, with the two sides reaching a series of "gentlemen's agreements", including a "new model" arrangement, to resolve the Ren'ai Jiao issue.

But instead of honoring its promises, the Philippines has been using various ploys to challenge China's historical, legitimate claim on Ren'ai Jiao and the relevant waters around it. For example, Philippine National Security Adviser Eduardo A?o, Defense Secretary Gilberto Teodoro Jr. and the Department of Foreign Affairs have recently issued statements denying the existence of any "gentlemen's agreements".

China, out of humanitarian concern, had allowed Philippine vessels to ship necessary supplies to the personnel on board the grounded warship on condition that Manila notifies Beijing in advance of any such plans. But Philippine government vessels and warships have repeatedly forced their way to Ren'ai Jiao, supplying construction materials to the personnel stationed there for overhauling and reinforcing the dilapidated vessel without prior notification. And that is the root cause of the tensions.

The Philippines has violated international law, as well as bilateral and multilateral agreements and arrangements, including the Declaration on the Conduct of Parties in the South China Sea (DOC) which the 10 member states of ASEAN and China signed in November 2002.

Article 5 of the DOC states: "The Parties undertake to exercise self-restraint in the conduct of activities that would complicate or escalate disputes and affect peace and stability including, among others, refraining from action of inhabiting on the presently uninhabited islands, reefs, shoals, cays, and other features and to handle their differences in a constructive manner." Article 7 further says the parties concerned should continue their consultations and dialogues on relevant issues, promote harmony, mutual understanding and cooperation, and make sincere efforts to resolve the disputes.

And Article 8 says the parties should respect the provisions of the DOC and take actions consistent with the DOC. All those bilateral and multilateral agreements and arrangements as well as international law require the Philippines to tow away its dilapidated warship, together with the navy personnel, from the Chinese territory of Ren'ai Jiao.

What has prompted the Philippines to violate the DOC rules, bilateral agreements and international law is the interference of the United States in the issue. In fact, Washington has been encouraging Manila to make provocative moves, including breaking DOC rules and bilateral and multilateral agreements, with the aim of using the resulting chaos to push forward its "Indo-Pacific" strategy. Washington has even sent military aircraft and warships to survey the area in the name of honoring the promises it has made in the US-Philippines Mutual Defense Treaty of 1951.

The US-Philippines treaty says the two sides recognize that an armed attack on one would be dangerous to the other's peace and safety as well and, therefore, pledge to take joint measures in such situations to meet the common dangers. And it stipulates that an armed attack on either party would be deemed an armed attack on both parties, or on the island territories under its jurisdiction in the Pacific Ocean, its armed forces, public vessels or aircraft in the Pacific.

Moreover, the new US-Philippines Bilateral Defense Guidelines of May 3,2023, reaffirm that an armed attack in the Pacific, including anywhere in the South China Sea, on the public vessels or aircraft of either party, including those of the coast guards or armed forces, would invoke mutual defense commitments under the 1951 treaty. Backed by the US, Philippine President Ferdinand Marcos Jr. said that even one Filipino serviceman's death in an attack by a foreign power would invoke the treaty. Marcos Jr. sees the treaty as the last life-saving straw, even though there are doubts over the commitment of the US.

Personal and family interests, too, are a major consideration for Marcos Jr.'s China policy. Being threatened by US agents that he would be ousted like his father was in 1986, Marcos Jr. has been complying with the US in exchange for protection and the return of the Marcos family's ill-gotten wealth. In doing so, however, Marcos Jr. has sacrificed Sino-Philippine relations.

He should realize that, in the long run, peaceful management and settlement of the maritime disputes through talks are in the best interest of both China and the Philippines.

The author is a research fellow with the Institute of International Law, Chinese Academy of Social Sciences.

The views don't necessarily reflect those of China Daily.

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