Honestly, everyone with a claim should be fortifying their claims since the decision to eject forces is a lot tougher to make (and get away with) than landing on unoccupied islands and announcing what was always yours is now secure. I'm shocked this hasn't been happening at a faster pace:
Kalayaan Mayor Eugenio Bito-onon yesterday said that Union Bank, a wide body of shallow water located well within the country’s 200-nautical mile exclusive economic zone (EEZ), is now teeming with construction activities not only by the Chinese but also by the Vietnamese.
If countries with claims don't stand on them, China will eventually get to each and every one of them.