This week, the Philippines and United States kicked off their largest-ever and most consequential joint Balikatan (shoulder-to-shoulder) war games featuring as many as 16,000 troops including 11,000 American servicemen.

Crucially, the two allies will conduct some of their drills outside the Philippines' 12 nautical miles "territorial sea" in the South China Sea, a direct challenge to China's expansive "nine-dash line' claim encompassing most of the international waterway.

In a move that will likely further irk China, the weekslong Balikatan exercises will also extend to the Philippines' northern province of Cagayan, which abuts Taiwan's southern shores.

The massive drills come on the heels of the historic Japan-Philippine-US (JAPHUS) trilateral summit in Washington, where US President Joe Biden publicly warned China of its mutual defense obligations to the Philippines in the event of a conflict in the South China Sea.

It remains to be seen whether Philippine President Ferdinand Marcos Jr will symbolically attend this year's drills. The leader has firmed up strategic relations with the US, including by allowing US forces rotational access to northern Philippine bases near Taiwan via the Enhanced Defense Cooperation Agreement (EDCA).

Marcos Jr had earlier in his tenure signaled commitment to diplomatic engagement with China by ruling out further expansion of US access to Philippine bases, a position he has since flip-flopped as tensions have spiked over contested South China Sea features.