The World's Dollar Drug

BY ZACHARY KARABELL

For all the talk about the problems of Greece and their implications for the euro zone, there is another currency that presents equally profound problems: the U.S. dollar. The dollar is, as everyone knows, the world's reserve currency, and it widely seen as a boon and an anchor for the emerging global economic system. It is also the only thing standing between the United States and its own moment of reckoning, and that is not a good thing.

The evolution of the dollar as the world's reserve currency tracked the emergence of the U.S. as a dominant power. The Bretton ...