The Jun 17 incident yielded some vital data points: Manila’s reticence to escalate tensions and Washington’s apparent ambivalence about committing more robust forms of support to the Philippines even without invoking the Mutual Defense Treaty.
China also demonstrated the lengths it could go to disrupt the Filipinos’ moves and its escalation dominance. The yawning capability asymmetry between the two countries was on clear display: The largest Chinese coast guard vessel, displacing over 10,000 tonnes, was deployed at close proximity to the Sierra Madre outpost barely a week after the fracas
https://www.channelnewsasia.com/commentary/south-china-sea-philippines-us-red-line-treaty-4443911