China is insisting that international agreements do not apply in its dispute with the Philippines over Scarborough Shoal. Chinese warships entering the Filipino exclusive economic zone (anything within 380 kilometers of land) are violating a 2002, agreement by nations bordering the South China Sea. Scarborough Shoal is 200 kilometers from the Philippines and 850 kilometers from China. After signing the 2002, agreement China changed its mind three years ago and is now claiming ownership of the entire South China Sea.
Today a Chinese military newspaper repeated the claim to Scarborough Shoal and warned that China would do whatever it takes to maintain its claim, no matter who (like the United States) backs the Philippines. That's pretty scary stuff coming from an official military publication.
The U.S. has nearly tripled its military aid to the Philippines this year. The Philippines is offering American forces more access to Filipino military bases (especially airports and ports). The U.S. left its military bases in the Philippines two decades ago (after being there for nearly a century). That was a popular move in the Philippines, where there is no popular support for reestablishing such bases. That kind of move is not popular in the United States either and there is even some reluctance to vigorously back the Philippines in its territorial disputes with China. All the U.S. will say is that it opposes the use of force in these disputes.