Numenor and America

[Firefoot]

Much of the symbolism I see in the Akallabeth applies not only to America, but to humanity itself.

In that, I think you hit the nail on the head. It is the way people are, and that is probably what Tolkien was able to see. Perhaps you can see it in America because you are American (as I am, myself), but I would imagine that, given the opportunity to be that way, people in most any country would behave in much the same way. Not all people, but many.