Why did the United States assume a preeminent world role after World War II, and why has that role declined since the Vietnam War? This magisterial book-the first intellectual and cultural history of America's evolving status as a world power in the twentieth century-addresses these questions by examining Americans' perceptions of themselves and of the world during this period. Drawing on the writings of leading intellectuals, speeches by politicians, popular periodicals, movies and television, opinion polls, and dozens of other sources, Donald W. White explores what Americans thought about power in the twentieth century, how they evaluated America's expanding world role and the confrontations of the Cold War, and how they perceived the erosion of this unprecedented accumulation of power in the years after the Vietnam War. With colorful anecdotal detail, White presents a new perspective on foreign affairs during these years, recounting the global spread of American democratic philosophy, technology, industrial goods, literature, arts, and way of life against a backdrop of military crises and diplomatic negotiations. In the process he identifies major trends in past American foreign policy and suggests possibilities for the prospects of international relations in the future.