Yesterday's much-anticipated S&P downgrade of U.S. treasury bonds is obviously a historic event.

It seems the world has spent the years since 2008 stumbling from one debt crisis to another. In fact, if we count the Third World debt crisis, which did after all affect most human beings on the planet, the world has been in a continual series of debt crises since the '70s. The difference is that until very recently, the U.S. was the ultimate arbiter of who owed what to whom, and on what terms. 2008 marked the moment when that...