"In a comparison of the Soviet and Nazi regimes, the political theorist Hannah Arendt wrote in 1951 that factuality itself "depends for its continued existence upon the existence of the nontotalitarian world." The American diplomat George Kennan made the same point in simpler words in Moscow in 1944: "here men determine what is true and what is false." Is truth nothing more than a convention of power, or can truthful historical accounts resist the gravity of politics? Nazi Germany and the Soviet Union sought to master history itself. The Soviet Union was a Marxist state, whose leaders proclaimed themselves to be scientists of history. National Socialism was an apocalyptic version of total transformation, to be realized by men who believed that race and will could slough off the burden of the past. The twelve years of Nazi and the seventy-four years of Soviet power certainly weigh heavily on our ability to evaluate the world. Many people believe that the crimes of the Nazi regime were so great as to stand outside history. This is a troubling echo of Hitler's own belief that will triumphs over facts. Others maintain that the crimes of Stalin, though horrible, were justified by the need to create or defend a modern state. This recalls Stalin's view that history has only one course, which he understood, and legitimates his policies in retrospect."