"All the concepts men live by are a product of the historic formation in which they find themselves.
"The man of the East cannot take Americans seriously because they have never undergone the experiences that teach men how relative their judgments and thinking habits are. Their resultant lack of imagination is appalling. Because they were born and raised in a given social order and in a given system of values, they believe that any other order must be 'unnatural,' and that it cannot last because it is incompatible with human nature." - Czeslaw Milosz, The Captive Mind
I think this goes a long way towards explaining current attitudes about a number of things here in the States, including but not limited to gay marriage and our not particularly nuanced foreign policy. We can't forget that the United States is a young strapping country (and 200+ years is very, very young) without the experience of our older neighbors to the east, and like an adolescent, I think we're often guilty of over-reacting and lashing out in ways that we may not when we're older and wiser.
Not to oversimplify, but our giddy emphasis on success, upon economic growth, upon the superficial display of wealth, and upon youth culture might be tied into this, too. No doubt, our relative geographic isolation and our disinclination as a people to travel abroad, compared with people of other nations only further contributes to the problem.