The sense of impending doom produced by Germany's defeats in the East had a progressively corrosive effect on morale on the German home front, but did not crucially impede the German war effort.
Hitler's Decision to Invade the Soviet Union
After assuming power in 1933, Hitler ended the secret collaboration between Germany and the Soviet Union under which Soviet officers were trained by the Germans and Germany developed new weapons in Russia in violation of the Versailles Treaty. The Nazi dictatorship liquidated the powerful German communist party. Stalin supported Western European efforts to restrain Nazi expansionism in the 1930s. In Mein Kampf, Hitler "blended into his obsessive antisemitism, aimed at the destruction of 'Jewish-Bolshevism,' the concept of a war in the East for 'living space' or Lebensraum," which was "needed for the 'master race' to sustain itself" (Kershaw 241 and 243). In August 1936, Hitler shared with Hermann Goering and a few other senior Nazi leaders his belief in "the necessity of war between Marxist Russia and Western civilization" (Overy 34-35).
However, under the Nazi-Soviet pact of August 1939, relations between Nazi Germany and the Soviet Union were temporarily patched up, which safeguarded Germany's eastern flank as it destroyed Poland. Stalin, disillusioned with the weak response of Great Britain and France at the 1938 Munich Conference to Germany's eastward expansion into Czechoslovakia, made a deal with Hitler t