I think it would happen along the same lines as what you said or just have another cold war. America doesn't want a war so I'll assume we'll do everything that we can not to have one. If it starts then North Korea will make the first move, so i think Europe and North America will rally. If there is one it should be relatively short w/ Russia on our side and their proximity to North Korea, we could end it hopefully within 2 years.
Edit: check this site for more info: http://www.nytimes.com/2009/04/04/world/asia/04korea.html?hp
I did post my message before reading the article so yay i'm right!