Strategypage notes that South Korea and China both expect the North to collapse:
North Korea accused the United States of carrying out 190 aerial recon missions against them in November. That would be entirely possible, because the rumors and scraps of information coming out of North Korea indicate that the government is falling apart. There have been more defections of senior North Korean government and military officials lately, and the border with China is more and more wide open to anyone with a little something to bribe the border guards with. For months, China has been moving more troops to their North Korean border. Partly this is to try and control the larger number of people fleeing the north, and to be ready if millions come across when the North Korean government collapses.
"When the North Korean government collapses." I hope we are pushing to help them along the way.
Could we really take care of the last two members of the Axis of Evil in the next four years?