If all else fails, the D.P.R.K. Army still has artillery dug in deep and close to the DMZ, a constant reminder of Seoul's vulnerability; if anyone attacks, all North Korea has to do is implement its "Porcupine Strategy" and pull the trigger. According to Pentagon estimates, a conflict in Korea would lead to 52,000 U.S. and 490,000 R.O.K. casualties within the first 90 days, and the former CIA director James Woolsey has argued that 4,000 daily air strikes over a period of 30 to 60 days would be required to annihilate Pyongyang's extensive nuclear program.

