Correct, but they won't use the nukes first because then they've got too much to lose, to little to gain.
Yes, other then military actions, a response by the US is very limited indeed, but the Bush administration isn't stupid - they won't launch any strikes, because the response by NK on SK would be horrific for the civilian population...
I'm not laughing or rejoycing because of the posibility the west coast would be nuked, your post proves only the fact that you don't know me and my stand on this. I'm not a mad man to wish deaths of millions of ppl, american or otherwise.