[yequalsx]

I think a lot of this has to do with the cultural starting point in the U.S. The idea of American exceptionalism is quite common amongst the political punditry. Say something often enough and it begins to get believed.

There was a time when it was common amongst the Chinese intellectual class to think China was the best. In the 1400's Chinese emperors acquired a very anti-foreign attitude and Chinese exploration declined rapidly. Roman citizens thought Roman civilization was the best. My point is, imperial arrogance is common.