Well, I don't think they are, but most of them certainly don't know much about geography or anything outside the States. Considering they are today's world leaders, maybe their education system should change dramatically to give them more information about the rest of the world. Their ignorance about all of us is funny... and scary! Watch this CNN clip.
Turn the full-screen button on to read the subtitles more easily (it's at the bottom of the video). But if you think Americans are not that stupid, then watch this other video about the British (British are also not stupid) and you will find out that you are probably right.