IT HAS NOT BEEN an especially good decade for the Japanese left. The old Socialist party has splintered. The main opposition party, founded in 1998, has absorbed former members of the right-wing Liberal party. (Its leader is now ex-Liberal boss Ichiro Ozawa, a prominent conservative.) The consensus on sundry foreign and defense policy matters has shifted rightward. And Japanese voters have elected their two most hawkish prime ministers since the mid-1980s.

Cause for alarm among the neighbors? Hardly. Japan still boasts the world’s most famously pacifist constitution. It still keeps military spending capped at an artificially low level. “Collective self-defense” remains a legal bugaboo. The nuclear “allergy” still pervades Japanese society. Indeed, Tokyo’s chief foreign policy adjustments in recent years have all been blessedly reasonable: beefing up the U.S. alliance, pursuing a missile defense shield, and moving toward a global security role commensurate with its economic power.