If we do go to war against the NK's again, China will definetely get involved again, but at least that'll give us an excuse not to pay our debt to them ha-ha. North Korea is a buffer for them. They would not like to have American troops or South Korean troops right on their border, heck, they would not like to have a prosperous capitalist nation on their border so China is what I'd be more concerned about than the NK people. I doubt the NK people will form some kind of insurgency, maybe just the people in Pyongyang, as that is where the most privileged class lives, but a lot of provinces have become more independent from the central government and, believe me, the "Dear" leader is not so dear in those areas. Maybe a better idea would be to just send them weapons and let them retake their own country and if they do run into trouble provide them some air cover.
Now, about a prosperous Korea after reunification. The people in North Korea for generations have lived under a totalitarian dictatorship which has provided their rations for everything, that is when they have enough to give out, so the concern I got is that they will not know how to make an honest living if reunified with the south. The South Koreans, from some reports I've read, are also concerned that the northerners when reunified will just be looking for their usual handouts, sort of what happened when Germany was reunified and the easterners expected their new capitalist democratic government to support them.
But the question is, can America fight in another front? Well, since we're expecting combat troops to leave Afghanistan soon and, from what I've heard, they have already left Iraq, it's not really fighting on another front then.
