Hitler Orders 'Aufbau Ost', the Mobilization of Troops as Preparation for the Invasion of Russia

Aufbau Ost (German: Building in the East) was the German operational code name for the mobilisation of forces prior to the commencement of Operation Barbarossa and the subsequent invasion of the Soviet Union.

On August 8, 1940 Hitler ordered Walter Warlimont, Deputy Chief of Alfred Jodl, to determine the positions of Soviet troops in the East. The appropriate directive was signed the next day by Wilhelm Keitel. It stated that due to the threat of British air attack on Eastern Germany it was necessary to use the eastern territories for drawing and preparing the new units. In compliance with the directive, the building organization of Fritz Todt started equipping the battleground while the rear organs managed the logistical support in the East. Meanwhile preparations for adjusting the Soviet rail gauge to match the Western European were taking place.

Hitler and the National Socialists saw the lands of the Soviet Union as prime settlement area for future long-term expansion of the German "race." They also defined the Soviet system as the political expression of the expansion of the Jewish "race." From the founding of the Nazi movement in Germany, the Soviet Union was portrayed as an enemy with which a showdown was inevitable.