June 22, 1941: Under the code name "Operation Barbarossa," the attack is launched on the Soviet Union. Now the war that was Hitler’s primary goal begins. The aim is to achieve multiple objectives at once: a permanent acquisition of "Lebensraum" in the East, the extirpation of Bolshevism, the "solution to the Jewish question," and exploitation of raw materials and labor.
For that reason, Hitler wages the war against the Soviet Union as a war of conquest and annihilation from the very start. The war in the Wehrmacht-occupied Balkans is of a similar brutality.
The main instrument in the war of annihilation is the SS and police structure commanded by Heinrich Himmler as "Reichsführer SS and Chief of the German Police." This includes the "security police" – in other words the "Secret State Police" (the Gestapo) and the criminal police – as well as the "Sicherheitsdienst des Reichsführers SS" (an intelligence service, also called the SD), together with the regular police and units of the Waffen-SS.
The Wehrmacht leadership and the army generals in the eastern theater support the reign of terror of the SS and police units in some cases, and at least tolerate it otherwise. Some Wehrmacht units are also directly involved in mass crimes.