how to "solve" the NK situation? Get bunker-busting nukes in case Kim thinks he's safe in his underground lair. Tell everyone and their dog that you have these nukes around, ready to waste a country's leaders. Perhaps you could go so far as to stop the MAD altogether, and use modern technology to "only" nuke these leaders. That'll get them thinking.
Another thing: if NK even *thinks* about nuking Japan, they're in for a shock. Japan has the capability to build nukes in a very short time, and might do that if NK goes wild on building their own nukes. Japan has indicated in the past that they will build and use nukes if they're forced to. I'd also like to point out that any nuke going from North-Korea to Japan will be followed by a nuke going from the US to NK; perhaps China will join in too. The fact that they'll use their nukes on their enemies is enough to make them a direct threat to the rest of the world.
...on the other hand: nobody will win in these scenarios.
