While Taiwan has long been considered a potential flashpoint between the U.S. and China, another geopolitical storm may be brewing in the South China Sea — one that could force Washington to make some difficult choices.

From laser pointers blinding Philippine sailors to collisions at sea near key military outposts, tensions are rapidly surging between Manila and Beijing in these strategically and economically important waters, where the two have overlapping claims.

By bolstering the country’s defense capabilities as well as deepening defense ties with the U.S. and like-minded countries such as Japan and Australia, Philippine President Ferdinand Marcos Jr. has taken a tough stance on territorial disputes with China — and he is backing this up with bold moves.