 The failure of Operation Barbarossa was a turning point in the fortunes of the Third Reich . Most importantly , the operation opened up the Eastern Front , to which more forces were committed than in any other theater of war in world history . The Eastern Front became the site of some of the largest battles , most horrific atrocities , and highest casualties for Soviets and Germans alike , all of which influenced the course of both World War II and the subsequent history of the 20th century . The German forces captured millions of Soviet prisoners who were not granted protections stipulated in the Geneva Conventions . Most of them never returned alive ; Germany deliberately starved the prisoners to death as part of a " Hunger Plan " that aimed to reduce the population of Eastern Europe and then re @-@ populate it with ethnic Germans . Over a million Soviet Jews were murdered by Einsatzgruppen death squads and gassing as part of the Holocaust . 
