Is the US the most powerful nation in the world because the US is in some ways special? Clearly, the US must have done some thing right. However, does this make the US exceptional, i.e. culturally or otherwise superior to everyone else?
The idea of American Exceptionalism isn't new as the Wikipedia entry makes clear. In fact, it is almost as old as the US. And, the US isn't even the first country to think of exceptionalism. The German's had a similar idea which ultimately led to the second world war. The Romans did too. As did the Greeks. In fact, the world 'barbarian' as used by the Greeks was meant to imply you couldn't speak proper Greek (equivalent to the Hindi "bur bur" or babble, so barbarians are babblers). The British, to paraphrase George Mikes, didn't actually say they were exceptional. They just fought such dangerous ideas in others while never actually saying who they thought was exceptional. :)
The Romans, in particular, grew powerful by conferring Roman citizenship on the power wielders, scientists, artists, etc. of the people they conquered (sound familiar). If it does, it isn't surprising. It isn't an accident that the National Monuments in DC look Roman or that Roman architecture inspired so much of the Third Reich architecture and motifs.
Does a belief in US exceptionalism matter?
One of the most interesting comments about the holocaust I had ever heard was from a history professor patiently trying to explain how otherwise good people could have let such crimes occur. His point was that if you dehumanize someone or something, you are no longer project your own emotions on them, and so, no longer feel their pain. So, your normal moral compass does not operate. The first step in dehumanization is to believe you are different, or worse, better.
I experienced the downside of a belief in US exceptionalism in a weird way. In 2002, I was in a conversation with a finance professor from a US University about how the US might have drawn lessons from the UK Cadbury Committee's Code of Best Practice in 1992 that may have prevented debacles like Enron. That, in fact, most of the Sarbanes Oxley Act drew on lessons that had been learned many times in many countries, and that the US might have been able to anticipate these issues, if they had assumed that the US is just as prone to these human tendencies as any other country. The professor, despite the evidence, wasn't willing to acknowledge that such lessons can be drawn. He went onto assert that, for instance, the US financial system was so sound and so much superior that debacles like the Japanese asset bubble and subsequent banking collapse could never happen here. :)
The idea of US exceptionalism has cropped its head up in recent times in rather more disturbing ways. It has been alleged that the neoconservatives were driven by the idea of American Exceptionalism, i.e. that the US is somehow special. Unfortunately, this quickly devolved into the belief that rules don't apply to the US. Neoconservatives used this theory to argue for the setting aside of foreign treaties, redefine torture, describe as "collateral damage" the deaths of hundreds of thousands in Iraq, and castigate as unpatriotic anyone who questioned the US.
It became an issue in the 2008 Presidential elections, where, Obama's lack of deference to the theory led to questions about his patriotism as articles like this remind us. Those who were driven to make these arguments seem to conflate exceptionalism with irreproachability.
So, perhaps, it wasn't surprising that Obama was confronted with a question on this very question on his European tour. Here is Obama's answer:
As answers go, this was perhaps one of the more eloquent. Without actually saying so, Obama drew a distinction of being proud of the very laudable and commendable things about the US, and drawing any conclusions about the US' inherent moral superiority or manifest destiny. Good stuff!