A Chinese dispute with the Philippines is a test of America

To grasp China’s approach to the international rule of law, look at the South China Sea. In recent weeks and months, large white-hulled ships belonging to China’s coastguard have been bullying small boats sent to resupply a rusting ship-cum-garrison purposely grounded by the Philippines—an American treaty ally—on a disputed coral atoll two decades ago. China claims that atoll, the Second Thomas Shoal, as its own. At the same time, fighter jets from the People’s Liberation Army (PLA) have repeatedly staged dangerously close intercepts of American reconnaissance flights in international skies close to China’s coasts.