This author seems to have a well reasoned solution to dealing with north korea.
http://www.politico.com/magazine/sto...jong-un-215411
The short version:
-Kim Jong Un is obsessed with getting nukes not because he wants to use them against us, but because he wants to continue to exist and not to become the next Saddam Hussein.
-Work to get more information to the north korean people about life outside their country to foment an eventual resistance.
-Convince the north korean elites that we will support them when they realize the time has come to abandon the regime so that they won't follow Kim into a deadly war that will have no winners.
-Plan for a "tear down this wall" point where the DMZ gets ended and the country reunified, and all that that will entail.
If we had a reasonably politically experienced president from either party I'd feel reasonably confident that things would play out this way in some fashion. I hope there are enough experienced people still hanging on in our government to steer things in some form in the direction of this author's suggestions. The alternative is too horrible to contemplate.