Joseph S. Nye Jr. in Foreign Policy:
Americans are prone to cycles of belief in decline, and the term itself confuses various dimensions of changing power relations. Some see the American problem as imperial overstretch (though as a percentage of GDP, the United States spends half as much on defense as it did during the Cold War); some see the problem as relative decline caused by the rise of others (though that process could still leave the United States more powerful than any other country); and still others see it as a process of absolute decline or decay such as occurred in the fall of ancient Rome (though Rome was an agrarian society with stagnant economic growth and internecine strife).
Such projections are not new. As Zakaria notes, America's Founding Fathers worried about comparisons to the decline of the Roman Republic. A strand of cultural pessimism is simply very American, extending back to the country's Puritan roots. English novelist Charles Dickens observed a century and a half ago: “[I]f its individual citizens, to a man, are to be believed, [America] always is depressed, and always is stagnated, and always is at an alarming crisis, and never was otherwise.”
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