The video may seem too simple, too understated to mark a serious international incident in the South China Sea: a quick clip of a diver using a knife to cut a section of rope underwater.

But that diver was with the Philippine coast guard, and the rope was part of a sea barrier placed by Chinese forces to keep Philippine boats away from an area they had a legal right to fish in. In that moment, the Philippines took one of the most forceful steps yet in contesting China¡¯s unrelenting territorial claims ever closer to the Philippine Islands.

¡°The barrier posed a hazard to navigation, a clear violation of international law,¡± the Philippines said in a statement, adding that the action had come on direct orders from President Ferdinand Marcos Jr.