Too bad Bush doesn't know the difference between a tough diplomat and a tough.
Or maybe he does, and has decided that the UN should become one more way in which the "talk radio" model should be applied to the world: Scream loudly enough and the reasonable will walk away in disgust, leaving you with the people who scream back.
It seems to have worked here, and in the US as a whole. Why not try it on the world stage? The illusion of dominance is more fun than the hard work of compromise and cooperation.