I thought this was a really good article by Newsweek (tho biased at points)... on IRC, someone scoffed when I said the US was currently a lone superpower. Take a good read at the article and then tell me if you still disagree. Some highlights:
A few months later [after 9/11] it [the US] toppled a regime [Afghanistan] 6,000 miles away - almost entirely from the air - in Afghanistan, a country where the British and Soviet empires were bogged down at the peak of their power.
The US will spend as much next year on defense as the rest of the world put together (yes, all 191 countries). And it will do so devoting 4 percent of its GDP, a low level by postwar standards.
The US economy is as large as the next three - Japan, Germany and Britain - put together.
There's more, but I leave it to an exercise to the reader to both see for themselves and save me from what is probably already a copyright violation.;)