Evidence continues to mount that Japan is adopting a more assertive role in international affairs, especially toward China. Just this week, Japan’s defense ministry issued a report charging that the country faced increasing threats from both China and North Korea. More notably, officials warned Beijing to stop trying to change its position in the region through intimidation or force.

In one sense, it may be beneficial to the United States if Japan begins to act like a normal major power in the international system. Tokyo has behaved for far too long as a quasi-pacifist country, heavily relying on the United States to manage East Asia’s security problems—and even expecting Washington to protect Japan’s own vital economic and security interests while Tokyo barely deigned to lend a helping hand. Japan’s long-standing, self-imposed limit of spending no more than one percent of the country’s gross domestic product on defense is just one sign of that unhealthy dependence. Whatever the wisdom of the United States playing the role East Asia’s security blanket in previous decades, when Japan and other democratic countries in the region were poor and weak, that strategy long ago outlived any usefulness it might have had. Today, it makes little sense for America to borrow money from foreign creditors, including China, to continue subsidizing the defense of such allies as Japan, which should be fully capable of providing for their own defense.

If Washington can off-load obsolete and risky security obligations onto Japan, Tokyo’s greater assertiveness is a welcome development. But if Prime Minister Shinzo Abe and other leaders merely want the United States to backstop a more aggressive policy in pursuit of parochial Japanese interests in the region, that is a worrisome, dangerous development. And there are signs that Tokyo is seeking such backing, especially regarding its territorial dispute with China over a chain of small, uninhabited islands (called Diaoyu in China and Senkaku in Japan).

As I wrote in the pages of the National Interest Online last year, the Senkaku/Diaoyu quarrel is potentially dangerous to the United States. Secretary of State Hillary Clinton stated in 2010 that Washington’s 1960 defense pact with Japan covers the Senkakus. Assistant Secretary of State for East Asia, Kurt Campbell, was equally definitive in September 2012, stating bluntly that the disputed islands were “clearly” covered by the treaty, which obliges the United States to come to Japan’s aid if attacked.

The Japanese government is doing its utmost to strengthen that attitude on the part of its American protector. The United States needs to take immediate steps to reduce its risk exposure. President Obama should overrule the State Department’s interpretation of the 1960 defense pact, and make it clear to Tokyo that, regardless of any previous positions Washington may have taken over the years regarding the islands, the United States is not about to risk going to war over some uninhabited rocks. It is also important to take that step before a crisis erupts.