Korean papers are reporting today that George W Bush has made a decision to support regime change in North Korea. This is huge, and no doubt I will come back to it. Integrating North Korea into South Korea is a task on a MUCH bigger scale than integrating the two parts of Germany was, and Germany has still not recovered from that.
The first problem to address, though, is how to get from here to there. Regime change does not necessarily mean war. Bill Clinton supported regime change in Iraq - but that is not much of an example, because his policies failed. North Korea also, probably, has usable nuclear weapons. They do not have missiles capable of hitting the US, but might be able to hit Japan or South Korea. Nuclear weapons do not, in any case, need missile delivery systems, and could theoretically be delivered in a suitcase.
In the case of North Korea, it may be necessary to think more laterally. The UN Security Council could authorise member states to take action, but instead of designating the United States to take the lead, as in the last Korean War, it could designate China. I don't think China wants North Korea for its own purposes, any more than the US does, but might nonetheless take on the role of leading an invasion.
My favourite possibility, however, is bribery. Why not simply offer Kim Jong Il large sums of money and guarantees of immunity to move somewhere else. It has to be worth a try. Since he is a film buff, I have even suggested in the past someone offers him a job as a Hollywood producer. He is an unreconstructed Stalinist, so he would fit right in.