I think the crux lies in the saying: MIGHT MAKES RIGHT. Americans believe this. Since WWII we've had the might to kick the rest of the world around, and we have no intention of giving up the associated "right", nor the idea that we are morally and ethically "in the right".

Ron Paul is definitely an exception to this bullying status quo among US politicians. He has said that his first order as president would be for the aircraft carriers to back away from Iran. He understands blowback and is willing to speak about it.