I think the recent procurement of centrifuges by NK posses the largest proliferation in the world right now. With everyone focused on Russia, the START treaty, and how to secure 'loose' nuclear material in the former Soviet Union, we may allow uranium to slip out of NK and into hostile regional state actors (or worse, terrorists). Yet we cannot ignore the threat of direct nuclear attack by NK.

When countries do not hold their population as valuable, and the leadership has proven that they have an erratic decision calculus, our form of deterrence fails. Since our national nuclear defense strategy depends on nuclear retaliation against anyone who initiates a nuclear attack, and we can’t guarantee North Korea won’t become a first strike nation, we cannot allow North Korea to possess nuclear weapons. If we did, the US may find itself in a situation where it is forced to use nuclear weapons against an inferior country or absorb a nuclear attack without retaliating. Both outcomes would significantly impact our national security objectives. We must declare to the international community that a nuclear North Korea is unacceptable, and commence diplomatic actions immediately FOLLOWING a low impact strike to destroy the centrifuges.

http://onparadox.blogspot.com/