Philippines Warns Chinese Attack on Grounded Warship Is Act of War Triggering US Pact

Philippine Defense Secretary Teodoro issued a stern warning today, taking a clear stance on the core flashpoint of the South China Sea dispute. He stated that if China uses force against the BRP Sierra Madre, the Philippine warship deliberately beached on Second Thomas Shoal, it would be considered a clear act of war. Furthermore, Teodoro emphasized that if Chinese personnel attempt to forcibly board the vessel, which has been stationed there since 1999, such provocative actions could directly trigger the 1951 Mutual Defense Treaty between the Philippines and the United States. This would formally draw the U.S. into the regional conflict, instantly escalating tensions in the South China Sea to unpredictable levels.

The BRP Sierra Madre, a World War II-era landing craft, has long served as a key symbol of the Philippines’ sovereignty claims and actual presence in the South China Sea. The Philippine Navy deliberately beached the ship on Second Thomas Shoal and deployed Marines to rotate guard duty aboard it, thereby asserting sovereignty and jurisdiction over the area. However, the aging warship is now in a state of severe disrepair, requiring regular resupply missions and structural maintenance to maintain basic operations. In recent years, Chinese Coast Guard vessels and maritime militias have frequently obstructed Philippine supply convoys in the area. The two sides have engaged in multiple dangerous incidents, including water cannon attacks and ship collisions, turning Second Thomas Shoal into one of the most volatile geopolitical powder kegs in the Indo-Pacific region.

The Philippine defense chief’s public drawing of a red line, explicitly outlining the severe consequences of military attacks or forced boarding, is grounded in the deep military alliance framework between the Philippines and the United States. The Mutual Defense Treaty stipulates that in the event of an armed attack in the Pacific area, both parties shall take action to meet the common danger in accordance with their respective constitutional processes. As the situation in the South China Sea has grown increasingly severe in recent years, Washington and Manila have repeatedly reaffirmed that the treaty applies to the Pacific region of the South China Sea, covering Philippine military, government vessels, and aircraft, including Coast Guard ships. Teodoro’s latest remarks serve as a confirmation, at the highest official defense level, to Beijing that the deterrent power of the U.S.-Philippines alliance is not merely theoretical.

From a geostrategic perspective, the South China Sea is not only one of the world’s most critical maritime trade routes, rich in fisheries and oil and gas resources, but also the main theater of strategic competition between China and the United States in the Indo-Pacific. China claims sovereignty over the vast majority of the South China Sea based on its "nine-dash line" and has continuously consolidated its de facto control in recent years through land reclamation, the construction of military facilities, and regularized maritime patrols. In contrast, after the administration of Ferdinand Marcos Jr. took office, the Philippines adjusted the previous administration’s more China-friendly diplomatic approach, actively strengthening security cooperation with like-minded nations such as the United States, Japan, and Australia. Through joint patrols and military exercises, the Philippines seeks to counter China’s expansionist pressure, making the resupply of the BRP Sierra Madre a key indicator for the international community to assess regional rules and order.

Should China actually launch a military attack on the BRP Sierra Madre or attempt a forced boarding, it would not only shatter the existing strategic balance but also force the United States to face the critical decision of whether to intervene directly in accordance with the treaty. Such a move would carry an extremely high risk of direct military confrontation between the two superpowers and would deal a devastating blow to the unity of the Association of Southeast Asian Nations (ASEAN) and regional stability. Most countries in the Asia-Pacific region have consistently called for restraint from all parties to prevent the South China Sea from becoming a battlefield for great power conflict. The latest warning from the Philippine Department of Defense serves as both a serious strategic deterrent and an alert to the international community, highlighting that the sovereignty dispute in the South China Sea stands at a crossroads where it could easily spiral out of control.

(Source: CNA)