A friend sent me the article from the Wall Street Journal,

Are Rome's Last Days a Distant Mirror for America?

It's at http://online.wsj.com/article/SB10001424052748704312504575619143718091672.html

It starts

"The disturbing aspects of this moment in history are the striking similarities between America's current direction and events that took place in the late stages of the Roman Empire. Rome was the world's only superpower in the late second century, A.D.; 100 years later, Rome was terminally ill, weakened first by internal corruption and unsustainable spending and then destroyed by the emergence of multipolar contenders for power."

I recommend reading the full article. The situations aren't identical, but the Roman experience sure gives one pause for thought! I read a very good book by Kevin Phillips (I think it was Wealth and Democracy), on how superpowers don't remain so. He was talking about Holland, then England, and now the U.S., more than Rome. He's written other good books, including American Dynasty, about four generations of the Bushes, and what they've done to the U.S.

I recommend you read both of these books, if you want a greater understanding of the current world.