The Nazis took the first step that led to mass murder on January 30, 1933, the day they seized power and established a totalitarian regime in Germany. Only a regime that tolerated no dissent was capable of carrying out the horrendous action of genocide. Although the Nazis obviously did not foresee the future, nevertheless in the 1930s they succeeded inadvertently in establishing some, but not all the preconditions for their later “accomplishments.” Yet, although the Nazis’ Jewish policy became increasingly brutal throughout the decade, the number of murdered Jews remained relatively small, perhaps in the hundreds.

The Nazis took the second major step toward the Holocaust on September 1, 1939, when they attacked Poland, thereby beginning World War II. Antisemitism played little role in Hitler's decision to attack Poland; nevertheless, in retrospect it is evident that killing millions of Jews could happen only within the inferno of a war. It is with the conquest of Poland, when the Germans set up ghettos that were from the outset instruments of murder, that the Holocaust began.