US sends defense treaty trigger warning to China

Washington has responded to the collision between Chinese and Philippine coast guard ships in the South China Sea early on Monday, reminding Beijing of the U.S.'s 73-year-old Mutual Defense Treaty with its oldest Asian ally.

"The United States reaffirms that Article IV of the 1951 U.S.-Philippines Mutual Defense Treaty extends to armed attacks on Philippine armed forces, public vessels, or aircraft—including those of its Coast Guard—anywhere in the South China Sea," Vedant Patel, a U.S. State Department spokesperson, said in a statement that day.

Article IV of the pact says that an attack on either country in the Pacific region would prompt the partnered countries to take action and "meet the common dangers" according to their constitutional processes.

The collisions occurred as the Chinese coast guard intercepted a pair of Philippine Coast Guard cutters near the contested Spratly Islands feature Sabina Shoal, which sits about 86 miles from the Philippine island of Palawan and within the country's internationally recognized exclusive economic zone.

A U.S. Marine directs his section of amphibious combat vehicles to the consolidation zone after live-fire training on May 4 in Oyster Bay, Philippines. The U.S. on August 19 condemned China after another confrontation between... Corp. Aidan Hekker/U.S. Marine Corps

Patel blamed China's coast guard for "causing structural damage and jeopardizing the safety of the crew onboard." "The United States stands with its ally the Philippines and condemns the dangerous actions by the People's Republic of China against lawful Philippine maritime operations in the South China Sea," Patel added.

He said China must adhere to international law and "desist from its dangerous and destabilizing conduct."

Mao Ning, Chinese foreign ministry spokesperson, said during Tuesday's regular press briefing that Sabina Shoal has "always" been Chinese territory. She reiterated Beijing's stance that the Philippines was responsible for the collision and said that China would "continue to take resolute measures to safeguard its territorial sovereignty and maritime rights and interests."

Beijing has blasted the Philippines for maintaining a weekslong coast guard presence at the uninhabited shoal, which, like most of the South China Sea, it claims is Chinese territory.

Meanwhile, China in early July parked its largest coast guard ship off Sabina for about a month before rotating in another to take up the watch. Ships belonging to China's so-called maritime militia also flooded into the area early on Monday, shiptracking data from Stanford University's SeaLight Project showed.

Ray Powell, director of Stanford University's SeaLight Project, told U.S. Naval Institute News that the collision had "opened up a new front" in the China-Philippines territorial dispute.

China's coast guard said its Philippine counterparts had rammed its ships after "illegally intruding." Manila accused the Chinese vessels of dangerous maneuvers and released photos showing "minor structural damage" sustained by the two ships in the collisions.

Monday's clash was the latest in a series of incidents, including collisions, unsafe approaches and water cannon blasts, over the past year as Chinese forces back Beijing's claims near South China Sea hotspots like Second Thomas Shoal; here, the Philippines keeps a garrison of Marines aboard a grounded warship.

Several Philippine military personnel have been injured, raising questions over what would trigger the defense treaty and potentially pit U.S. and Chinese forces against each other. Philippine President Ferdinand Marcos Jr. in May said that a "willful act" resulting in the death of a Philippine national would almost certainly be a red line.