A large part of diplomacy seems to be finding ways to say things you can't say. I greatly admire the Japanese announcement about missing plutonium recently. On the surface, it is an honorable admission of fault in their disastrously careless nuclear energy program. But in the context of North Korean threats, it carefully hints that Japan might have some plutonium available for secret projects. It does nothing so blatant as say "We reserve the right to make our own nukes." That would cause some domestic uproar, and knot up the underwear of Pacific rim states. "Nuclear bomb" isn't a safe phrase to use in Japanese politics. But who could take issue with such an innocuous confession?