The issues and lessons raised by the Holocaust go far beyond the immediate horror of the events themselves. They include the whole problem of how democracies maintain themselves in a world in which by living up to their own principles they put themselves at risk. The style of a terrorist movement is predictive of the kind of government it will operate if it comes to power, and genocide is one of its logical options. Societies that are attempting to maintain the creative tension between liberty and popular sovereignty will recognize that terrorist movements are, by self-definition and chosen style of action, outside the arena of full, free, and informed discussion that informs a free society. The task of democratic societies is to create a body of laws that protects loyal citizens in the exercise of their liberties, while at the same time rendering impotent potentially genocidal movements in time .
Some people have a very simple answer.
They wave the populist slogans of the nineteenth century and arrive at what is today known as totalitarian democracy. By the time the Nazis assassinated German Foreign Minister Walter Rathenau in July 1922, they and their immediate allies had already killed 344 political opponents. We did not understand it then, of course, nor did we understand it in 1933. We did not even understand the truth in 1938 in most parts of the so-called civilized world. Ingmar Bergman once used a very vivid metaphor in explaining his movie The Serpent's Egg.