Tensions between China and Japan have erupted in the East China Sea over the five small, uninhabited islands the Japanese refer to as the Senkaku and the Chinese call the Diaoyu. The islands have been the subject of competing sovereignty claims by China, Japan, and Taiwan for decades. For the past several years, Chinese and Japanese naval and air forces have come in frequent contact as China and Japan have sought to demonstrate control over the islands. Given that their militaries are increasingly in contact in the waters of the East China Sea and the airspace above it, the risk of a miscalculation or accident has risen, raising concerns that the sovereignty dispute could lead to an armed clash between Asia’s two largest powers.

The United States has a long-standing policy of neutrality on the islands’ sovereignty. However, the United States is treaty bound to defend Japan, an ally, in the event of an attack. The United States also has a strong interest in maintaining a stable relationship with its largest trading partner, China. Accordingly, the United States needs to consider what price it would be willing to pay to fulfill its treaty commitment to Japan’s defense. Such deliberation is particularly important given that a change in U.S. policy or a U.S. intervention could alter the United States’ relationship with China or Japan and jeopardize other pressing interests that require the cooperation of either country. These interests include nuclear nonproliferation, global economic growth, climate change mitigation, and the safety of Americans abroad.