Hey, if the U.S. really wanted to beat the crap out of any other two nations on the planet, they could do it. They have the technology, the nukes, the resources, the economic strength, and the manpower, if they really wanted to do it. The U.S. lost in Vietnam because they committed only a fraction of their resources to it; they could have blown the place back into the Stone Age if they'd really wanted to. But they didn't want to, and don't want to do that to anyone else either, for which we should all be grateful. Anyone who doubts that they could is deluded.
We should, in my view, be grateful that the U.S. is as sane and civilized as it is, and that its founding fathers were as wise as they were. They created institutions and safeguards that have protected their Great Republic from leaders who were stupid, ignorant, corrupt, arrogant, even insane; the nation has endured all of that and more, and still for most of its history has been held up as a shining example to the world of all that is best and most noble in human nature. Read the Declaration of Independence, and the U.S. Constitution. The great ringing phrases in those documents are powerful statements of what any free person values most. Yes, sometimes the U.S. fails to live up to the values and virtues that created it, but as Christ said, let he who is without sin cast the first stone. Yes we should criticize the U.S. when we disagree with its policies and behaviours, yes we should criticize its leaders when we think they're behaving badly, but never forget the ideals that lie at the heart of the United States. I believe they will triumph eventually, because there have always been enough intelligent and forceful people in the United States to force decency upon it. The U.S., for instance, didn't really lose the war in Vietnam as much as it was forced to quit by the revulsion of its own citizens against their government's behaviour. I expect something similar will eventually happen with Iraq.
The U.S. is a global superpower much the same as Britain was in the 19th century, but in the 19th century there was serious competition from other nations. Now there isn't. The U.S. stands alone at the pinnacle as no other nation ever has. Bitch and criticize, sure, with the U.S. you can do that without being shot. Be glad it's as benign as it is.