The missionaries of Christianity had said in effect: You have no right to live among us as Jews. The secular rulers who followed had proclaimed: You have no right to live among us. The German Nazis had at last decreed: You have no right to live.

The Holocaust was an unprecedented crime against humanity that aimed at the annihilation of the entire Jewish population of Europe, down to the last man, woman, and child. It was the planned, deliberate policy decision of a powerful state, the Nazi Reich, which mobilized all of its resources to destroy an entire people. The Jews were not condemned to die for their religious beliefs or for their political opinions. Nor were they an economic or military threat to the Nazi state. They were killed not for what they had done but for the simple fact of their existence.

To be born a Jew, in the eyes of Adolf Hitler and the Nazi regime, meant that one was a priori not a human being and therefore unworthy of life. There were other innocent victims of Nazi racial ideology: Gypsies, who were considered racially impure, were sent to the gas chambers; Russians, Poles, and other occupied peoples in eastern Europe were reduced to slavery; even those ethnic Germans who were branded as mentally or physically defective were put to death until a public outcry moderated this policy. We know that under the Nazi regime, the SS, the Einsatzgruppen (mobile killing units), the Wehrmacht, the Order Police, and the guards in the death camps practiced brutality on a hitherto unknown scale; that they mowed down row upon row of shivering, half-naked adults and smashed the heads of Jewish infants without pity or remorse; that they built a vast system of concentration camps and death camps, the purpose of which was the production of corpses on an industrial scale.

The central unanswered question is why? Why were Jews worked to death on senseless, unproductive tasks, even when the Reich was experiencing an acute labor shortage? Why were skilled Jewish armament workers killed in the camps despite the pressing military needs of the Wehrmacht? Why did the Nazis insist they were fighting an omnipotent "Jewish" power even as their mass murder of the Jews revealed the powerlessness of their enemy?

At the heart of this seeming mystery lay a millenarian weltanschauung (worldview) which proclaimed that "the Jews" were the source of all evils -- especially internationalism, pacifism, democracy, and Marxism; that they were responsible for Christianity, the Enlightenment, and Freemasonry. They were branded "a ferment of decomposition," form-lessness, chaos, and "racial degeneration." The Jews were identified with the fragmentation of urban civilization, the dissolving acid of critical rationalism, and the loosening of morality. They stood behind the "rootless cosmopolitanism" of international capital and the threat of world revolution. In a word, they were the Weltfeind -- the "world enemy" against which National Socialism defined its own grandiose racial utopia of a Thousand-year Reich.

In Hitler's genocidal, racist ideology, the redemption (Erlösung) of the Germans and of "Aryan" humanity depended upon the "Final Solution" (Endlösung) of the "Jewish question." Unless the demonic Weltfeind was annihilated, there would be no "peace" in a Europe that was to be united under Germanic leadership so that Germany could fulfill its "natural destiny" by expanding to the east to create Lebensraum (living space) for its people. The Second World War, which Hitler initiated, was simultaneously a war for territorial hegemony and a battle against the mythical Jewish enemy.

War made the Holocaust a concrete possibility. The victories of the Wehrmacht brought millions of Jews under the heel of German power for the first time. The task of annihilating them in cold blood was delegated by Hitler to the SS, under Reichsführer Heinrich Himmler and his closest sub-ordinate, Reinhard Heydrich. As early as 1939, a so-called euthanasia program, directly responsible to Hitler and the Führer Chancellery, had been initiated to eliminate nearly ninety thousand ethnic Germans who were deemed "unfit to live" because they were physically or mentally "defective." This program, halted temporarily in 1941, proved to be a training ground for the "Final Solution." In late 1941, its personnel, apparatus, and experience in killing by poison gas was transferred to death camps in Poland to be used against the Jews.

The Holocaust required more than an apocalyptic ideology of anti-Semitism in order to be implemented. It was equally the product of the most modern and technically developed society in Europe -- one with a highly organized bureaucracy. The streamlined, industrialized mass killings carried out in death camps such as Auschwitz-Birkenau and Treblinka were of a form unknown in European and world history. But millions of Jews were also killed by the Germans and their helpers via more primitive, "archaic" methods in Russia, eastern Europe, and the Balkans. The Einsatzgruppen and police battalions hunted down Jews and executed them in gruesome pit killings, in forests, ravines, and trenches. Russians, Poles, Serbs, and Ukrainians, although not earmarked for systematic mass murder, were also decimated in large numbers. Three million Soviet prisoners of war died in German captivity.

Some, such as Daniel Goldhagen, have argued that the Germans carried out these murders because they were Germans; their political culture and mind-set, grounded in a nationalist pride in their Volk, had been preprogrammed by an "eliminationist anti-Semitism" that had existed since at least the mid-nineteenth century. But before Hitler, völkisch racist anti-Semitism had not made great inroads in Germany, though it was far from negligible. Anti-Semitism had been much stronger and more influential in Tsarist Russia, Romania, or in the Habsburg Monarchy and its successor states, especially Poland, Slovakia, and Austria. Germany before 1933 was still a state based on the rule of law, where despite long-standing prejudice Jews achieved remarkable economic success, were well integrated into society, enjoyed equal rights, and decisively shaped its modernist culture.

Hitler's rise to power would not have been possible without the carnage of the First World War, the traumatic impact of German military defeat, the humiliation of the Treaty of Versailles, the economic crises of the Weimar Republic, and the fear of Communist revolution. Anti-Semitism, while central to Hitler, Joseph Goebbels, Himmler, Jules Streicher, and other Nazi leaders, was not the main vote-getter of the movement. But once racist anti-Semitism became the official state ideology of the Third Reich, reinforced by an extraordinarily powerful propaganda apparatus and a barrage of anti-Jewish laws, its impact was devastating.

It is, however, important to realize that the receptiveness of Germans (and other Europeans) to the demonization of the Jews owed a great deal to the much older tradition of Christian anti-Judaism. The Nazis did not need to invent the images of "the Jew" as a usurer, blasphemer, traitor, ritual murderer, dangerous conspirator against Christendom, or a deadly threat to the foundations of morality. Both secular rulers and Christian churches had ensured that (until the French Revolution) Jews were pariahs in European society, condemned to positions of inferiority and subordination. Racism had been used in Catholic Spain in the fifteenth century, for example, to justify the removal of even converted Jews from public functions and positions of economic influence.

The Protestant Reformation, especially in Germany, brought little improvement in the status of the Jews. Martin Luther's anti-Jewish diatribes would moreover become a contributing factor in the complicity of so many German Protestants with Hitler's deeds during the Third Reich's anti-Semitic persecutions. Catholics, too, were increasingly implicated in anti-Semitic political movements in France, Austria, Hungary, Slovakia, Poland, and other European states in the nineteenth and twentieth centuries. During the Holocaust, many Catholic clerics, like their Protestant counterparts, were often indifferent or even hostile to Jews. The deep ambivalence of the Vatican and the Christian churches cannot, however, be understood without taking into account the long-standing "teaching of contempt," which had deep roots in the New Testament itself and in the teachings of the Church Fathers. Nazism, though ultimately determined to uproot Christianity, built on the negative stereotypes about Jews and Judaism that the churches had disseminated for centuries.

The Germans did not carry out the Holocaust alone, although under Nazi rule they were undoubtedly its spearhead and driving force. When it came to killing Jews, they found many willing collaborators and "helpers" among Lithuanians, Latvians, Ukrainians, Hungarians, Romanians, Croats, and others. Austrians (who had been annexed to the German Reich in 1938) formed a wholly disproportionate number of the SS killers, death-camp commandants, and person-nel involved in the "Final Solution." Even official France "collaborated" eagerly, not in the killing of Jews but in their deportation eastward and in the passage of draconian racist legislation.

The Holocaust was a pan-European event that could not have happened unless millions of Europeans by the late 1930s had wished to see an end to the age-old Jewish presence in their midst. This consensus was especially strong in the countries of east-central Europe, where the bulk of Jewry lived and retained its own national characteristics and cultural distinctiveness. But there was also a growing anti-Semitism in western Europe and America, tied to the hardships caused by the Great Depression, increased xenophobia, fear of immigrants, and the influence of fascist ideas.

This hostility was evidenced by the unwillingness of British and American decision-makers to undertake any significant rescue efforts on behalf of European Jewry during the Holocaust. Already in the 1930s, the quota system in the United States had precluded any mass immigration of Jews from central and eastern Europe, which might have relieved some of the enormous pressures on Jewry. British concerns about Arab unrest in Palestine, following increased Jewish immigration in the 1930s to their "national home," led to another major refuge being denied them. Hitler duly noted these responses and the appeasement policy of the West before 1939 and drew his own conclusions: his expansionist ambitions could be pursued without too great a risk, and the West would not interfere with his increasingly radical anti-Jewish measures.

The Jews of Europe, on the eve of the Holocaust, found themselves in a trap from which there appeared to be no escape. They were faced with the most menacing and dangerous enemy in their history -- a dynamic power in the heart of Europe that openly sought their destruction. Its influence was felt in neighboring states, especially to the east and southeast, which were passing laws of their own to restrict Jewish rights and pushing for the removal or emigration of their Jewish populations. Moreover, the three million Jews in Communist Russia were cut off from the rest of the Jewish world; yet the identification of Jews with Bolshevism had become a highly dangerous political myth that would eventually fuel the mass murders carried out by the Nazis and their allies on the eastern front after June 1941.

The Jews of America were limited in what they could do for European Jewry by a combination of their own insecurity, their fears of anti-Semitism, and the reality of American isolationism prior to late 1941. The Jews of Palestine were still a relatively small community under British control and faced with a hostile Arab majority. The Zionist movement, while growing, was too fragmented politically and fractious to be effective.

The Nazi myth of the Jews as a well-organized, international power with clearly defined goals and common "racial" interests could not therefore have been further removed from reality. The Jews were in fact disorganized, relatively powerless, and lacking in solidarity or any agreed political agenda. Before and during the Holocaust they did not have a state, an army, a common territory, or a flag, let alone a coherent organizational center.

Except in rare cases, such as Denmark, Finland, Italy, and Bulgaria (which had relatively small Jewish populations), the Jews would moreover be cruelly disappointed by the lack of solidarity shown them by most of their Gentile neighbors once the dark night of persecution descended upon them. Even more bitter was the ease with which the protection of European states and governments was withdrawn and their rights were sacrificed as if they were absolute pariahs, beyond the pale of civilization. Hitler's war thus found many Jews trapped and virtually defenseless against a ruthless enemy bent on their total destruction in a world largely indifferent to their fate.

From this searing and potentially shattering trauma, the Jewish people nonetheless rose up after the Second World War to establish their own independent state. Other nations and minorities also learned the price of powerlessness after the Second World War and have fought to achieve their freedom from totalitarian tyranny and foreign oppression. But the Holocaust also has more universal lessons: it reminds us that xenophobia, racism, and anti-Semitism can lead to group violence and atrocities on an unimaginable scale; and that any society -- however culturally, scientifically, and technologically advanced -- can become totally criminal once it loses its ability to distinguish between right and wrong. The Holocaust underlines the danger of trusting in the idolatry of power without ethical restraint. It drives home the lesson that each individual is responsible for his or her own conscience and fate. It is a warning from history that obeying orders can be no excuse for criminal acts.

If there is a general lesson, then, it is that we must learn that evil can and must be resisted in its early stages; that we always have choices; and that there can be no place for racism and anti-Semitism in a civilized society. Thinking about the Holocaust is like staring into an abyss and hoping it will not stare back. It is the ultimate extreme case, a black hole of history that not only challenges our facile assumptions about modernity and progress but questions our very sense of what it means to be human.