The twentieth century did not turn out to be quite what Henry Luce (head of Time, Inc.) had in mind when, at the start of 1941, he declared it “The American Century.” “We have,” Luce claimed, “that indefinable, unmistakable sign of leadership: prestige,” which, he elaborated, “is faith in the good intentions as well as in the ultimate intelligence and ultimate strength of the whole American people.” The United States, he noted, was “already a world power in all the trivial ways,” including the influence of Hollywood movies, jazz, American slang, and its control of major patented products. It had also already made its mark in science, literature, and the graphic and performing arts. He regretted, however, that in its self-satisfied isolationist absorption during the first forty years of the century, America's failure to use its power responsibly had cost it some prestige. “But most of it is still there,” he concluded. He looked forward to the United States taking on its responsibilities as a nation of great resources by accepting the burdens of leadership.

After 1941, the United States would indeed take on a leadership role as one of the world's “superpowers,” with dramatic effect on global politics and economy. Its military power would help turn the tide against fascism in Europe and Asia and then hold the line against the expansion of Soviet communism. Its political and economic systems would in many respects become models for many countries of the world where, at least before 1940, liberal democratic institutions had had little apparent attraction.