As I see it, the US views itself as the center of the world, but the vast majority of Americans have such a provinsional world view.  My guess is that most Americans have never been outside their own continent.

I think you are quite right there. A majority have probably never been outside their state.

I have this feeling that the US has some sort of inherent identity crisis, in the sense that the US identity is only defined when compared to an enemy, such as the Nazis, the Communists and now the Terrorists.  In other words, the US NEEDS an external enemy to find their own identity.  Does this make any sense?

Perhaps we don't even need an external enemy but ones from within as well. Sad.