Its much simplier. UN get North Korea into a tight corner. There was no way out of there. And there is no way out of there for now. North Korea have nothing lef

Its much simplier. UN get North Korea into a tight corner. There was no way out of there. And there is no way out of there for now. North Korea have nothing left to do except surviving at all costs. To defeat enemy make him to face difficult choices where all the options are equally bad. When you give him exactly one difficult option, there is not choice at all for him, and that allows him to concentrate on fighting. He still could lose, but it will be much harder for you to win. To give different options to North Korea would mean for UN to admit ther mistakes, and that more important to hurt their ideologic feeling. Its a stalemate. Ideology against ideology.