Andrew J. Bacevich is professor of history and international relations at Boston University. He is editor of The Short American Century: A Postmortem, just published by Harvard University Press.

As someone who teaches both history and international relations, I have one foot in each camp. I'm interested in what has already happened. And I'm interested in what will happen next. In my teaching and my writing, I try to locate connecting tissue that links past to present. Among the devices I've employed to do that is the concept of an "American Century."

That evocative phrase entered the American lexicon back in February 1941, the title of an essay appearing in Life magazine under the byline of the publishing mogul Henry Luce. In advancing the case for U.S. entry into World War II, the essay made quite a splash, as Luce intended. Yet the rush of events soon transformed "American Century" into much more than a bit of journalistic ephemera. It became a summons, an aspiration, a claim, a calling, and ultimately the shorthand identifier attached to an entire era. By the time World War II ended in 1945, the United States had indeed ascended—as Luce had forecast and perhaps as fate had intended all along—to a position of global primacy. Here was the American Century made manifest....

Luce's essay manages to be utterly ludicrous and yet deeply moving. Above all, this canonical assertion of singularity—identifying God's new Chosen People—is profoundly American. (Of course, I love Life in general. Everyone has a vice. Mine is collecting old copies of Luce's most imaginative and influential creation—and, yes, my collection includes the issue of February 17, 1941.)

Alas, the bracing future that Luce confidently foresaw back in 1941 has in our own day slipped into the past. If an American Century ever did exist, it's now ended. History is moving on—although thus far most Americans appear loath to concede that fact....