MANILA - An attack by China on the BRP Sierra Madre at the Ayungin Shoal (Second Thomas Shoal) in the West Philippine Sea will trigger the Philippines’ Mutual Defense Treaty with the United States, former Foreign Secretary Albert Del Rosario said Thursday.

BRP Sierra Madre, which was grounded in the shoal in 1999 after China seized the Mischief Reef a few years earlier despite being within Philippine waters, “is a public vessel of the Philippines that is protected by Article IV of the 1951” treaty, said Del Rosario, who served during the administration of the late President Benigno Aquino III.

The defense pact binds the two countries to aid each other in the event of foreign aggression.

“If China attacks BRP Sierra Madre and our armed forces in Ayungin Shoal, such action would trigger the mutual defense commitments under the treaty where the US and the Philippines will act ‘to meet [such] common danger’ instigated by China,” the country’s former top diplomat explained.

The same position was also spelled out by the US State Department.

"The United States stands with our Philippine allies in upholding the rules-based international maritime order and reaffirms that an armed attack on Philippine public vessels in the South China Sea would invoke U.S. mutual defense commitments under Article IV of the 1951 U.S. Philippines Mutual Defense Treaty," said Ned Price, spokesman of the department, last Nov. 19.

• US nagbabala sa Tsina hinggil sa panghaharang sa Ayungin Shoal

The Chinese coast guard blocked and used water cannon on Philippine supply ships at the Ayungin Shoal last Nov. 16, claiming it is part of their territory. The mission was aborted and resumed Tuesday after Defense Secretary Delfin Lorenzana communicated with Beijing's envoy in Manila.

• DFA: Chinese Coast Guard vessels blocked PH supply boats in Ayungin Shoal
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Del Rosario said “the Philippines has every right to station BRP Sierra Madre in Ayungin Shoal, which is within the Philippine exclusive economic zone, under the United Nations Convention on the Law of the Sea, and as specifically affirmed by the July 12, 2016 UNLCOS award.”

• Lorenzana says China is trespasser at Ayungin Shoal; UNCLOS, arbitral award back PH claim

The Philippines' arbitration case against China over their maritime disputes in the South China Sea was initiated by the Aquino administration.

Beijing, which prefers to settle the issue bilaterally, did not participate in the proceedings and does not recognize the 2016 ruling that invalidated its claims over almost the entire South China Sea.

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Del Rosario described as ridiculous China's demand for the Philippines to remove the BRP Sierra Madre as supposedly committed by the latter.

"As affirmed by Defense Secretary Delfin Lorenzana, there is no such 'commitment' made by the Philippines," he said.

• China tells PH to remove BRP Sierra Madre from Ayungin Shoal

He urged the country's leaders and people "to continue to fight and resist Chinese efforts to take away the West Philippine Sea from Filipinos."

BRP Sierra Madre, he said, is an important outpost in the Ayungin Shoal for the country to resist the "illegal and oppressive incursions of Chinese forces in the West Philippine Sea."

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President Rodrigo Duterte condemned the recent incident in the Ayungin Shoal, and said the government views it with "grave concern." The development also does not bode well with the country's relations with China.

Duterte forged friendlier relations with China upon assuming power in 2016 to get economic aid and investments. He set aside the arbitral ruling, and said he does not want to provoke a war with China.

The Philippines has so far filed 211 diplomatic notes against China since Duterte became president amid continuing incursions in the country's waters, according to the Department of Foreign Affairs.

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