OPEC did not actually refuse to export oil to the U.S. -- it refused to sell oil on the world market for U.S. dollars. OPEC nations were smart enough to figure out that the U.S. was about to embark on a period of deliberate inflation of the U.S. dollar, thereby serving as a disincentive for foreign exporters to accept dollars as payment for their products. You might be interested in this thread
But if you try and warn people that this happened once and is likely to happen again (and soon), you get jumped on and called a commie liberal Bush-hater...and those are the more polite names ;)
I suspect that this is one of the primary reasons why the U.S. has refused to ratify Kyoto. The U.S. will continue to exert an enormous amount of leverage on the oil/currency scene as long as we are the world's largest consumer of this commodity.
Putin is no fool -- he's been to Texas enough time to realize that there is no future in selling oil to Europeans who work 35 hours a week, bathe once a month, and drive around in cars made out of popsicle sticks and aluminum foil.
If nothing else, I would hope that this discussion will drive the U.S. government to clean up its finances in a big way.