Operation Barbarossa

In the early hours of 22 June 1941, Nazi Germany and its allies launched Operation Barbarossa, a surprise invasion of the Soviet Union along a front stretching from the Baltic to the Black Sea. Involving several million troops, thousands of tanks and aircraft, and a front of well over a thousand miles, it was the largest invasion in the history of warfare. It opened the Eastern Front, where most of the fighting and killing of the Second World War in Europe would take place, and it ultimately sealed the fate of Hitler's regime.

The invasion grew out of Hitler's long-held ideological aims: the destruction of what he called "Judeo-Bolshevism," the conquest of "living space" (Lebensraum) in the east, and the exploitation of Soviet land, grain, and oil. Germany and the USSR had signed the Molotov-Ribbentrop Pact in August 1939, dividing Eastern Europe into spheres of influence and allowing each side to pursue its own aims for a time. After the fall of France in 1940, Hitler ordered planning for an attack on the Soviet Union. Stalin received numerous warnings of the coming assault but, for reasons historians still debate, discounted many of them and was reluctant to provoke Germany.

The attack began with massive air strikes and artillery bombardment, and three German army groups advanced toward Leningrad, Moscow, and Ukraine. Soviet forces, poorly positioned and disorganized after the purges of the officer corps in the late 1930s, suffered catastrophic losses. Huge numbers of soldiers were encircled and captured in battles such as Białystok–Minsk and Kiev. Behind the advancing army, special SS units and police formations carried out mass shootings of Jews and others, marking a turning point toward the Holocaust. Millions of Soviet prisoners of war would die in German captivity from starvation, disease, and neglect.

Despite stunning early gains, the offensive fell short of its goals. The Germans had planned for a quick victory in a matter of months and were poorly prepared for the vast distances, strained supply lines, autumn mud, and brutal winter. In December 1941 a Soviet counteroffensive pushed German troops back from the gates of Moscow, ending hopes of a rapid triumph. The Soviet Union relocated much of its industry eastward and mobilized its population on an enormous scale.

The consequences were immense. Germany was drawn into a prolonged two-front war, and the Soviet Union became a key member of the Allied coalition. The Eastern Front produced battles such as Stalingrad and Kursk and ended with the Red Army in Berlin in 1945. Soviet deaths in the war are usually estimated in the tens of millions, including civilians, and the conflict shaped the postwar division of Europe and the beginning of the Cold War.