I'm not sure how I feel about this. On the one hand, i'm always grateful when enemies end a cycle of aggression. At the very least, the US and SK might be able to use some of their defense budget spent on keeping NK under constant guard on more worthwhile investments (jesus aren't i optimistic).
On the other hand, that means that Kim Jong-Un's regime gets to keep it's stranglehold on the people of North Korea. Nearly 25 million people, and what we've seen of their lives from those refugees that crossed the DMZ does not paint a pretty picture. Is peace really worth it, if it means you're consigning a huge chunk of people to such a horrible life?
Well, I'll try to stay happy about it anyway.
To answer your question: Yes. The world does not need more Iraq, Libya, Syria, Afghanistan adventures to bring peace and liberty at the point of a bayonet; overwhelming force is not the only tool in America's arsenal, but it is certainly the one least suited to deployment for peace, especially at such a corner of the world which would see war between China and the US begin. If the state of the North Korean people is grim now, the toil that would be inflicted upon them by the demands of war - both allied and enemy, would be immensely magnified. The destruction of the North Korean leadership would be a highly achievable objective, yet likely to be replaced by the next Korean strongman capable of bringing order out of the chaos.
To do nothing, allow the smuggled cellphones and computers bring knowledge to North Koreans over the outside world, allow the regime to wither away or reform of its own accord, it is the path most likely to guarantee both peace and liberty for the whole Korean peninsula. The fate of North Korea is largely in the hands of China; and China has taken its steps to economically reform China, but remains firm to its own tight control over political authority. Thus the most realistic objective unlikely to get North Koreans turned into jelly by North Korean tanks is secure economic liberty, but not political liberty, which is a slightly more tolerable situation