U.S. President Barack Obama’s visits at the end of last week to Japan and South Korea were meant to underscore the United States’ commitment to its East Asian allies, particularly in defending them against North Korea.

Most experts agree that this commitment would be easier to fulfill if Seoul and Tokyo got along better. However, the trilateral summit in late March between Obama, South Korean President Park Geun-hye and Japanese Prime Minister Shinzo Abe in the Hague was notable, and not just because North Korea test-launched missiles during it: It was their first formal meeting since the two East