Yet again this Sunday, Thomas L. Friedman used his column in The New York Times to issue an ominous warning about America’s decline. Quoting from Lewis Mumford about the moral decadence of imperial Rome, he commented: “It was one of those history passages that echo so loudly in the present that it sends a shiver down my spine—way, way too close for comfort.” He ended the column with a call for a third-party candidate in 2012 with the courage to say to the voters: “I am going to tell you what you need to hear if we want to be the world’s leaders, not the new Romans.”

Friedman is sounding a popular theme. A Google search for the phrase “America’s decline” turns up 42,500 hits. Comparisons to Rome and other once-powerful empires abound, as in Cullen Murphy’s popular 2007 book Are We Rome? The Fall of an Empire and the Fate of America. From the Tea Party right comes the constant, screeching cry that President Obama and the Democrats are “destroying America.” The National Intelligence Council itself, a few years ago, predicted the “erosion” of American power relative to China and India. Clearly, the most popular classical figure in America today is that high-strung Trojan lady, Cassandra.

If we can be certain of anything, it is that some day the United States will indeed cease to exist. “If Sparta and Rome perished, what state can hope to last forever?” asked Rousseau in The Social Contract. The timing, however, is another matter. Why should we assume that we are just now sliding helplessly towards the edge of the cliff?

Twenty-two years ago, in a refreshingly clear-sighted article for Foreign Affairs, Harvard’s Samuel P. Huntington noted that the theme of “America’s decline” had in fact been a constant in American culture and politics since at least the late 1950s. It had come, he wrote, in several distinct waves: in reaction to the Soviet Union’s launch of Sputnik; to the Vietnam war; to the oil shock of 1973; to Soviet aggression in the late 1970s; and to the general unease that accompanied the end of the Cold War. Since Huntington wrote, we can add at least two more waves: in reaction to 9/11, and to the current “Great Recession.”

Trolling back through the older predictions of decline and fall can make for amusing reading. In 1979, just two years before George F. Will joined Ronald Reagan’s “Morning in America” chorus, he was lamenting in Newsweek: “When, as lately, America’s decline accelerates, it is useful to look back along the downward, crumbling path.” In 1987, as the Soviet Union stumbled towards its final collapse, the book that dominated conversations in Washington was Paul Kennedy’s The Rise and Fall of the Great Powers, which predicted the eclipse of the United States.