Luce’s formulation—that America uniquely embodies ideals of freedom and democracy and thus has a special mission, and dispensation, to promote them—is now often called “American exceptionalism.”

Peter Beinart: Left and right have abandoned American exceptionalism

Fifteen months later, at the Commodore Hotel in New York, Wallace—then Franklin D. Roosevelt’s vice president—answered Luce. “Some have spoken of the ‘American century,’” he noted, but “I say that the century on which we are entering—the century which will come into being after this war—can be and must be the century of the common man.”

Luce’s and Wallace’s visions differed in two critical ways. First, Wallace denied that America had any special or inherent claim on democratic ideals. “We ourselves in the United States,” he declared, “are no more a master race than the Nazis.” When citing models he hoped other nations would follow, Wallace mentioned not only the American Revolution but also “the French Revolution of 1792, the Latin American revolutions of the Bolivarian era, the German Revolution of 1848,” and, more dubiously, “the Russian Revolution of 1917.” The implication was that global progress would flow from a partnership of nations, each of which boasted traditions of liberty, rather than domination by an America that would mold the world “for such purposes as we see fit and by such means as we see fit.”

Secondly, Luce and Wallace disagreed about the kind of postwar economic order that would allow liberty to thrive. Luce emphasized that Nazism was “national socialism,” part of “the trend toward collectivism” that he decried in both Joseph Stalin’s Soviet Union and Roosevelt’s United States. In the American century, he insisted, a “system of free economic enterprise” must prevail.

Wallace, by contrast, saw unchecked private wealth as a threat to liberty. The “common man,” he argued, must “have the opportunity to form unions and bargain through them collectively.” If Luce saw Nazism as a species of socialism, Wallace saw it as the result of a toxic alliance between demagogues and big business. Citing “Herr Thyssen, the wealthy German steel man” who “gave Hitler enough money to enable him to play on the minds of the German people,” Wallace warned of “wealthy men who sincerely believe that their wealth is likely to be safer if they can hire” tyrants who “lure the people back into slavery.”

The Luce-Wallace debate ended conclusively: Luce won. After World War II, America took a hard line against the USSR, and America’s anti-Soviet alliances—in particular NATO—eclipsed the United Nations as the primary vehicles of American foreign policy. The phrase “century of the common man” faded into obscurity, but “American century” became a touchstone for hawkish politicians and commentators interested in signaling their support for American power and virtue. In 1997, William Kristol and Robert Kagan established the Project for a New American Century. In 2016, Marco Rubio made “A New American Century” his campaign slogan.