MANILA, Philippines — The United States renewed a warning Tuesday that it is obligated to defend its close treaty ally, the Philippines, following an incident where Filipino navy personnel were injured, and their supply boats were damaged in a serious confrontation with China in the disputed Second Thomas Shoal in the South China Sea. This incident marks one of the most severe clashes between the two nations in the contested region.

China and the Philippines have each blamed the other for instigating the confrontation on Monday at the Second Thomas Shoal. The shoal has been occupied by a small Filipino navy contingent aboard a grounded warship, the BRP Sierra Madre, which has been closely monitored by Chinese coast guard, navy, and suspected militia ships in a long-standing territorial standoff. There is a growing concern that such disputes could escalate, potentially drawing the United States and China into a larger conflict.

U.S. Deputy Secretary of State Kurt Campbell discussed China's actions with his Philippine counterpart, Maria Theresa Lazaro, in a telephone call. Both officials agreed that China's "dangerous actions threatened regional peace and stability," according to State Department spokesperson Matthew Miller. Campbell reaffirmed that the 1951 Mutual Defense Treaty, which obligates Washington and Manila to defend each other in major conflicts, "extends to armed attacks on Philippine armed forces, public vessels, or aircraft — including those of its coast guard — anywhere in the South China Sea," Miller stated.

A Philippine government task force overseeing the territorial disputes condemned what it described as "dangerous maneuvers, including ramming and towing," which disrupted a routine effort to transport food, water, and other supplies to the Filipino outpost aboard the BRP Sierra Madre at the shoal. "Despite the illegal, aggressive, and reckless actions by the Chinese maritime forces, our personnel showed restraint and professionalism, refrained from escalating the tension, and carried on with their mission," the task force said. "Their actions put at risk the lives of our personnel and damaged our boats in blatant violation of international law."

The Chinese coast guard, however, placed the blame on the Philippines, stating that a Philippine vessel "ignored China’s repeated solemn warnings ... and dangerously approached a Chinese vessel in normal navigation in an unprofessional manner, resulting in a collision." According to China’s Foreign Ministry, two speedboats attempting to deliver construction materials and other supplies to the military vessel stationed at the shoal accompanied the supply ship. The ministry described the coast guard’s maneuver as "professional, restrained, reasonable, and lawful."

Philippine Defense Secretary Gilberto Teodoro Jr. responded strongly, asserting that the country's armed forces would resist "China’s dangerous and reckless behavior," which he said "contravenes their statements of good faith and decency." Teodoro emphasized the Philippines' commitment to protecting its territorial integrity, sovereignty, and sovereign rights. "It should now be clear to the international community that China’s actions are the true obstacles to peace and stability in the South China Sea," he added.

The Second Thomas Shoal lies less than 200 nautical miles from the nearest Philippine coast, within the country's exclusive economic zone (EEZ). The BRP Sierra Madre, deliberately grounded in 1999, serves as an actively commissioned military vessel. An attack on it could be perceived by the Philippines as an act of war. Recent months have seen several incidents near the shoal, reflecting China's increasing assertiveness in pressing its claim to virtually the entire South China Sea, leading to rising tensions with other countries in the region, particularly the Philippines and Vietnam.

A new law enacted by China, which took effect Saturday, authorizes its coast guard to seize foreign ships "that illegally enter China’s territorial waters" and to detain foreign crews for up to 60 days. This law renews a reference to 2021 legislation permitting China’s coast guard to fire upon foreign ships if necessary. Coastal governments with claims to the waters — the Philippines, Vietnam, and Taiwan — have stated they will not recognize the law. Malaysia and Brunei are also involved in the long-seething territorial disputes, which are seen as a delicate fault line in the ongoing U.S.-China rivalry in the region.

The escalation of tensions in the South China Sea underscores the need for continued diplomatic efforts and international cooperation to manage and resolve disputes peacefully. The situation remains volatile, with the potential for further confrontations that could have significant implications for regional and global security.

This recent incident has reignited calls for an international code of conduct to govern behavior in the South China Sea, aiming to reduce the risk of accidental clashes and ensure that disputes are managed through legal and diplomatic means. The Philippines has reiterated its commitment to upholding international law, specifically the United Nations Convention on the Law of the Sea (UNCLOS), which supports its claims and rights in the contested waters.

In the wake of these developments, the international community, including ASEAN members and key global powers, is watching closely, recognizing the critical importance of maintaining stability in one of the world's busiest maritime regions. The actions taken by China and the responses from affected nations will likely shape the geopolitical landscape of Southeast Asia for years to come.