Chinese ships have repeatedly rammed Philippine ships in the South China Sea. The U.S. has a mutual defense treaty with the Philippines, which could lead to American intervention.

China has unleashed a new wave of attacks on the Philippines in the disputed waters of the South China Sea. The Philippines was forced to bring back one of its largest coast guard ships after frequent encounters with Chinese vessels.

The move to secure Australia’s strategic interests is likely to earn China’s ire and increase the potential for sanctions, analysts say.