This is a regional problem, first and foremost, is it not? --even if we get involved in conflict. It's time the East pony up to its responsibilities in those nations' new-found "sophistication."
If war it is, it needs to be an Eastern war.
The Unites States of America may strike preemptively with nuclear weaponry against a coming attack upon our nation, but we can clearly tell NK's "neighbors" that we don't intend to do that, for their sake.
It's up to them, to defend themselves against the worst that NK can do. Period.