Now that the 20th century is at last "history", what does this enhanced perspective tell us about the relationship between that century's two great threats to liberal democracy, Nazism and Communism? During the high Cold War decade following 1945, the matter appeared simple to the majority of Western opinion: the two systems should be equated in their infamy. Yet, as anti-Communism came under fire in the 1960s, and as the Cold War itself dwindled into detente in the 1970s, the Hitler-Stalin comparison largely fell into disrepute. At the end of the 1980s, however, European Communism's ignominious end re-opened the question, thus inaugurating a decade of debate over the issue of which "totalitarianism" was the greater scourge. Nor will this issue ever really go away again. For while Nazism and Communism are most unlikely to recur in the historical forms in which we knew them, the political impulses underlying them are still at work in modern political culture, indeed in the human condition itself.
Thus far, however, the renewed debate has suffered from an exceptional imbalance between heat and light. And this is because when we ask whether it is Communism or Nazism that must be judged the greater evil, we are too often unclear about what exactly should be compared in order to frame an answer. The usual procedure is to contrast inventories of horror: numbers of victims, means and circumstances of their deaths, types of concentration camps. Yet how do we make the transition from the raw facts of atrocity to a judgment of their moral meaning? Why, for example, is the industrialized extermination mounted by Hitler more evil than the "pharaonic technology" employed by Stalin and Mao Zedong? It would be an error to suppose a simple or direct answer to such a question. Rather, this greatest of vexed issues handed down from the 20th century must be approached on three interrelated levels: moral, political and historical.
