You guys have that problem in the UK, too.

Definitely, there is a subgroup that seems to think that the empire never declined, but they are a minority, a vocal one to be sure, but still a minority. More to the point, it isn't ingrained in the public subconscious, you are more likely to see people taking a 'plucky little Britain' view (which can be more or less justified, as long as it applies only post WWII) than one of current British superiority on the back of achievements from a century ago.

Hell, much of the UK population goes the other way, there is a significant proportion of the uninformed public who will tell you that the UK is degenerate and on the point of collapse, usually on the basis of foreign immigration, the Euro, the youth being lazy or the education system.. But overall I would say that there is a decent spectrum of positions, there isn't one that informs some sort of British superiority in all things, certainly not one that has been elevated to the point of being exported and informing foreign policy (the difference between US and UK rhetoric with regard to war is quite interesting in that regard).

My point is, I don't think you're really talking about an "American" problem. You're talking about an ignorance problem, and the UK and the US have their fair share of ignorant people.

Everywhere does. I think my point is that in the US it has so far had far more of an impact on politics and society as a whole. The UK makes some poor decisions and is certainly moving in the direction that the US is in now, but quite slowly and I think it will probably change course before it gets close to where the US is now (largely because the US does actually exercise military and economic dominance, or rather has, in a way that the UK simply cannot). Of course the UK is also very different from the US in a poitical sense, gain it is less polarised and less commercialised.

Yes, Americans do have a narrow world view; but so does most everyone in the entire world. You only know best what you experience the most; and ignorant people have fewer experiences (and no country has a shortage of ignorance).

This is where I would disagree. The US is certainly not unique, but it is close to being so. I have traveled quite extensively and the two countries that stood out in this regard were the US and Australia. The interesting point is that It is fairly obvious almost immediately, news broadcasts are shockingly country bound for example. Most Asian countries I managed to spend time in (including a few years in Hong Kong) and almost every European state on the other hand are far more broad in their influences and what they take in terms of news, culture and so on.

Part of that last point is probably because the US is a mass producer of media and so is culturally self-sufficient and self re-enforcing, but things like Bollywood releases for mass consumption seem far more common and accessible in Asia and Europe, as is Asian media (although less so in Europe).

In short, I don't think general ignorance is sufficient to explain US insularity, nor would I say that geographic isolation is an excuse for it. There is something in the combination of patriotism, exceptionalism and an insular trend that manages to feed on itself to an excessive level.