Something is going on in North Korea. An impending overthrow? Death of Kim Jong-Il? Something else?
Bottom line: He is being destabilized and the people there have had enough. Chia head sits on a power keg below him, and Uncle Sams obliterating power hanging above him, overhead. All he can really do at this point is release some pressure, step up his internal security, and big even deeper holes near Mt. Paektu to hide in at the appropriate time.
The poor NK people are the key to their future if/when they can uprise. They need the truth first, and then additional resources. This is a long struggle, but it is now well underway, IMHO.
IMO Kerry was very close to blowing out of the water a strategy that was in the works.