The issue of nuclear proliferation trumps all others. If this matter is not handled correctly, it can literally have "Fall of Rome" consequences in our lifetimes. The Obama administration has been aggressive in it's approach to Pyongyang and our provocative posture is beginning to bear fruit. The North Koreans use brinksmanship all too often and it is time that their bluff is called. For the first time in forty years, the South is uniting behind a militant policy towards their belligerent neighbor.
Lets push harder - right now - in an effort to humiliate Kim Jong Il and his heir apparent son. They will have the option of escalating - a point beyond which they utterly lose the whole game - or backing down and losing the confidence of the Peoples Army and the Central Committee. Finally, China will understand that their ongoing support of Pyongyang is simply too expensive. The stakes are too high to let this tiny regime continue to thwart the will of the international community and stir up the possibly of nuclear weapons programs in Tokyo and Taipei.
What if they escalate? What do we do then? We have sufficient, massive airpower to quickly punish the North Koreans. It would be bloody, indeed, however their wad would be exhausted early on and artillery damage to Seoul would likely be far less than has been feared. The upside of such a war would be the end of the North Korean nuclear threat. We would have nipped it in the bud at great expense, however, at a tiny fraction of the potential cost in the years ahead.
Would they go nuclear? Thats highly doubtful. In fact, the evidence suggests they do not have a reliably deliverable bomb. If our shock and awe was properly targeted, we could take this possibly entirely off the table at the onset of hostilities. Obviously, they would know that going nuclear meant certain suicide - the US would be in a position to answer quickly and finally.
The "Two for One" nature of the victory is obvious. North Korea's success to date has emboldened the Iranians. Teheran would pay close attention to the events in Korea. If Pyongyang's nuclear production is shut down, Iran's would soon follow. There would be a new proliferation paradigm in place and it would not be hospitable to new nuclear states. Quite the opposite.