China and the Philippines are edging dangerously toward armed conflict in the contested South China Sea, a potential clash that could quickly escalate into a US-China conflict in the world's most vital seascape.

On April 30, China Coast Guard (CCG) vessels used water cannons against two Philippine vessels conducting patrols close to the contested Scarborough Shoal, a sea feature both sides claim.

The Chinese vessels targeted the Philippine Coast Guard's (PCG) BRP Bagacay and Bureau of Fisheries and Aquatic Resources (BFAR) vessel BRP Datu Bankaw, both of which sustained damage, according to Philippine authorities.

"This damage serves as evidence of the forceful water pressure used by the China Coast Guard in their harassment of the Philippine vessels," Commodore Jay Tarriela, spokesperson for the National Task Force for the West Philippine Sea (NTF-WPS), said in a statement.

To be sure, China has yet to employ armed force to impose its will on the Philippines. And it has yet to reclaim the hotly-disputed Scarborough Shoal, which has been under Beijing's de facto control following a months-long standoff in 2012.

But the Philippines is being pushed to the edge as China continues to injure its maritime personnel and damage its vessels. This week's attack came just weeks after another incident at the Second Thomas Shoal that injured several Filipino servicemen.

Significantly, the Scarborough Shoal incident coincided with major Balikatan wargames between the Philippines and key allies, most notably the United States, which deployed 11,000 troops and state-of-the-art weapons systems and simulated amphibious attacks on islands.

Pressure is growing on the US to respond to China's aggression. The Joe Biden administration has repeatedly warned Beijing of its obligation to come to Manila's rescue in the event of a conflict.