Apologies if someone has already linked to this
http://www.washingtonspeakers.com/pr...Game.07.05.pdf
It's a report on a wargame/brainstorming session held in 2005 by "The Atlantic" magazine. The results (and opinions) make interesting reading. Incidentally, the pdf also mentions a 1961 treaty that - if NK is invaded - obliges China to commit troops in support of North Korea.