re: Comparing with Vietnam
1) involving the UN which didn't approve of the war, therefore isolating the US.
I'm not trying to be snide about this, but I think this is actually more troublesome to those outside the US than to Americans themselves. Most Americans, from what I can gather, aren't really bothered by this. Faith in the UN is, generally speaking, rather low here.
Don't get me wrong, I don't think many Americans want the country to be isolated (and it's arguable as to whether that really is the state of affairs, anyway). But--and I say this without bravado--the US isn't afraid to walk alone if need be. Especially after 9/11.