It was bound to happen eventually.
I say we bomb the **** out of North Korea. No nation building this time.
If we have to overthrow the Kims, then I prefer going for the Marshall Plan approach once we've liberated (no sarcastic "quote" lines, we actually would be liberating it) North Korea. After all, the North Koreans will either have to stay in North Korea, or flee en masse to South Korea or China. But if we just leave North Korea itself as is, it'lll be 100 times worse than the economic imbalance between East and West Germany.
Let China deal with the consequences. They've been propping up this human rights disaster since the 50's. They can handle the refugees.
This would potentially cause a global depression if the Chinese were unable to cope.