How an Alliance System Withers

Washington Is Sleeping Through the Japanese-Korean Dispute. China Isn’t.

Wu Hong / Reuters

For more than half a century, U.S. power in Asia has rested on the alliance system that Washington built in the years after World War II. Now, a dispute between Japan and South Korea—the two most important pillars of that system—threatens to undo decades of progress. But instead of seeking to actively mediate between its allies, Washington has largely watched from the sidelines—leaving the field to China, which has moved quickly to benefit from U.S. inaction. At a trilateral summit with the Japanese and South Korean foreign ministers in late August, for instance, China encouraged the …