It has been frequently pointed out that President Bush plays poker, not checkers. Two destroyers w/missile destroying capability are now near N. Korea...imo an answer to the question of 'what can we do?'
They've also stepped up the pace (and the announcements about) the Airborne Laser anti-missile program.
That's all in the last week!
I remember how back in the first Gulf War there was an airborne side scanning phased array radar program at about the same phase of testing (Joint STARS). They just said "fly it over there" and it proved itself in combat, even surpassing the original design capabilities. I don't know if there are technical hurdles with the ABL program that would keep them from doing that, but then, neither does Kim.