For years there has been a left-wing historiographical taboo against comparing Communism and Fascism. But despite the fact that, with the collapse of Communism, this taboo has been lifted, many questions of comparison remain unsettled. Should one emphasize the similarities between totalitarian political regimes (Stalin’s Soviet Union and Hitler’s Third Reich) or their differences? By highlighting the thesis of "fraternal enmity," and the political features these regimes shared, as Ernst Nolte has done in his exchange with François Furet, one risks, in the case of Nazism, of lapsing into apologetics. That Nazism took hold in one of the West’s most advanced industrial societies and that Stalinism, conversely, took root in a context of underdevelopment, suggests that, in the last analysis, the differences between these two totalitarian formations outweigh their similarities.