The ‘‘unipolar moment’’ that followed the Cold War was expected to start an era. Not only was the preponderance of U.S. power beyond question, the facts of that preponderance appeared to exceed the reach of any competitor. America’s superior capabilities (military, but also economic and institutional) that no other country could match or approximate in toto, its global interests which no other power could share in full, and its universal saliency confirmed that the United States was the only country with all the assets needed to act decisively wherever it chose to be involved. What was missing, however, was a purpose- a national will to enforce a strategy of preponderance that would satisfy U.S. interests and values without offending those of its allies and friends. That purpose was unleashed after the horrific events of September 11, 2001. Now, however, the moment is over, long before any era had the time to get started.