Submariner is correct. The main means we have to handle Korea at this point is deterrence. Neo-conservative columnist Charles Krauthammer wrote his
last column on this topic that I think is close to correct (even though I hate his guts).
He wrote that it was too late to either buy the North Koreans off or to wage war to disarm them. His solution was a two pronged nuclear deterrant. First, that we should nuke North Korea if they launched nuclear missiles (obvious). But he also wrote that we should also threaten to nuke NK if a terrorist anywhere in the world used a nuke. The logic behind this is that if a terrorist got his hands on a nuke, according to Krauthammer it would be a pretty safe assumption that it came from NK because NK is the only "rogue state" with nukes. I don't think its that simple because there is the problem of loose nukes from the former Soviet Union, but he is correct in that deterrence is the best way to handle NK.