The Philippines has worked with a number of countries since 2023 to assert its rights and maritime entitlements in the South China Sea.  MANILA: The navies of the Philippines, the US and Japan trained alongside each other in the South China Sea this week to ramp up cooperation among the military allies, the Philippines' armed forces said on Friday (Feb 27).  Since 2023, the Philippines has worked with a number of countries to assert its rights and maritime entitlements in the South China Sea.