Fueled by China’s increasingly emotional ambition, tensions in the South China Sea are rising quickly. The result is a situation in which a U.S.-China conflict is considerably more likely than is commonly assumed.

The tension has been encapsulated over the past few days by competing U.S. Navy and Chinese People’s Liberation Army Navy exercises. China’s exercises were focused around the contested Paracel Islands chain 180 miles south of China’s Hainan Island territory. But each nation’s exercises had two key purposes.