On 22 June 1941,
Adolf Hitler abruptly broke the non−aggression pact and
invaded the Soviet Union. The Soviet territories occupied by early 1942, including all of Belarus, Estonia, Latvia, Lithuania, Moldova, Ukraine and most Russian territory west of the line Leningrad–Moscow–Rostov, contained about four million Jews, including hundreds of thousands who had fled Poland in 1939. Despite the chaos of the Soviet retreat, some effort was made to evacuate Jews, who were either employed in the military industries or were family members of servicemen. Of 4 million about a million succeeded in escaping further east. The "Holocaust by bullet" was the task of SS death squads called
Einsatzgruppen, under the overall command of
Reinhard Heydrich. These had been used on a limited scale in Poland in 1939, but were now organized on a much larger scale. Most of their victims were defenseless Jewish civilians (not a single
Einsatzgruppe member was killed in action during these operations). They used their skills to become efficient killers, according to
Michael Berenbaum. By the end of 1941, however, the
Einsatzgruppen had killed only 15 percent of the Jews in the occupied Soviet territories, and it was apparent that these methods could not be used to kill all the Jews of Europe. Even before the invasion of the Soviet Union, experiments with killing Jews in the back of vans using gas from the van's exhaust had been carried out, and when this proved too slow, more lethal gasses were tried. Units of the Wehrmacht also participated in many aspects of the Holocaust in Russia. == The Holocaust in the RSFSR ==