North Korea is a real problem, no doubt. The belligerence of this rogue state is the best of all possible arguments for deposing Saddam and preventing Iran from preceding with its own nuclear weapons program. One of the rare points of agreement between both the Kerry and Bush camps in 2004 was that our biggest concern is nuclear proliferation.
I don't have any solutions. Diplomacy is our only option - with Iran, because our military is stretched too thin for action on the ground; for North Korea, precisely because it does have the bomb. (A most devilish cycle - we can't let any more outlaws get the bomb, but every outlaw wants it because it makes it so difficult to deal with them).
It's worth noting, though, that many democracies have the bomb, and no one is worried about, say, England, going on a nuclear bender. This makes the pro-liberty foreign policy push of the Bush administration more crucial than ever; if nuclear weapons must exist, and exist they do, then let us at least have them in the hands of democracies. No wonder every president leaves office with gray hair and a thousand wrinkles.