The minute the United States lobs a few bombs North Korea's way, Seoul will be smashed by approximately 8,000 North Korean artillery capable of delivery approximately 500,000 rounds per hour (not the small arse rounds, mind you). If Kim is irrational enough to use nukes, Tokyo would be a #1 target with their intermediate ballistic missiles, with the possibility of Seattle (ironic that I live there), Los Angelos, Honolulu being a prime target for their intercontinental ballistic missiles.
It would take a massive nuclear pre-emptive strike to nullify just the North Korean artillery batteries pointed at Seoul to the point of no threat. However, South Korea, China, Russia, and Japan would protest the nuclear strikes because of the nuclear fallout (because we all just love living in post nuked land dont we?). In other words, no, Bush doesnt have what it takes to actually stand up to a real foe, or a "dilemma" in general.