I don't think N. Korea would take the first shot at the U.S.  I find it hard to believe Kim is even that crazy.  There's no way he'd win a shooting war with this country.  With even China turning their back on N. Korea, it's Kim against the world.  What I do think he's doing is trying to make the U.S. look like the bad guy and maybe even get us to shoot first, although I still don't know how that would benefit him.  He might take a shot at S. Korea with his conventionals, once he has the tech to actually deliver a nuke.  Again, not sure how that would benefit, either.

I think it's a bunch of hot air, personally.  Can't see a way of Kim winning any military confrontation.  I've no idea of the mentality of his citizens, though.  Maybe they even believe in the guy?