Based on optimistic assumptions about how a collapse might occur, we estimate that 260,000–400,000 ground force personnel would be required to stabilize North Korea. This means that even in the relatively benign scenario that we describe, the requirements for stabilizing a collapsed North Korea would outpace the combined U.S. troop commitments to Iraq and Afghanistan. Managing a more demanding Korean collapse scenario would push these requirements higher or lengthen the duration of the operation, or possibly both.

The short answer: not very well.  That’s the subject of my first post over at the Washington Post’s polling blog, Behind the Numbers.  It features this graph from