The largest military operation of World War II, Operation Barbarossa was the codename for Nazi Germany’s invasion of the Soviet Union. Named for 12th-century crusader and Holy Roman Emperor Frederick Barbarossa, the Axis operation included more than 4.5 million troops over a 1,800-mile (2,900-km) front. Though the Red Army suffered heavy losses, Operation Barbarossa failed and marked a turning point in the war that many believe sealed the Nazis’ fate. How many were killed during the operation? Discuss