Oh! and is all forgot? … Were we fools then, or are we dishonest now?
—William Hazlitt, in The Spirit of the Age

Almost twenty years ago, on one of my periodic assignments in Europe for The New York Times, I had a conversation over lunch one day with one of the paper’s older foreign correspondents that made a great impression on me. The war in Vietnam had recently ended—for the Americans, that is—and at lunch that day we fell to speculating about what long-term effects that conflict would have on the United States and its role in the world. The Cold War was still raging, of course. Aleksandr Solzhenitsyn had been expelled from the Soviet Union, yet his reception in the West was anything but cordial. Washington had entered upon a period of détente in its relations with the Kremlin, and harsh criticism of the Soviet...