NARA/U.S. Department of Defense

June 22 marks the 75th anniversary of the launch of Operation Barbarossa, the Nazi invasion of the Soviet Union. Although the initial offensive caught the Soviets completely by surprise, penetrating hundreds of miles into Soviet territory and netting hundreds of thousands of prisoners, the advance eventually stalled in the face of Soviet resistance and the onset of “General Winter.”

In the days before the outbreak of World War II, Adolf Hitler and Joseph Stalin had concluded the Molotov-Ribbentrop Pact, a nonaggression treaty that secured Germany’s eastern flank and divided eastern Europe into German and Soviet spheres of influence. Stalin’s purge of the Red Army in 1937 had decimated the military’s high command, and the Soviets’ dismal performance against the heavily outnumbered Finns in the Russo-Finnish War (1939–40) had convinced Hitler that the Soviets were a threat that could be easily overcome. Indeed, the initial German successes seemed to support that conclusion.

Those successes came too late in the campaign season, however. The June 22 invasion date was more than a month later than German planners had intended, as Italian misfortunes in Greece and a coup in Yugoslavia had caused a redirection of German forces to the Balkans. By the time Fedor von Bock’s army had reached the suburbs of Moscow, winter had set in. Army Group North under Wilhelm von Leeb had settled into a protracted siege of Leningrad, and German troops along the line of advance found themselves ill-equipped to battle both the elements and a group of increasingly competent Soviet commanders. Although Germany continued to press the attack until disastrous battles at Stalingrad (July 1942–February 1943) and Kursk (July–August 1943), the failure of the initial blitzkrieg to achieve its objectives before the onset of winter had effectively consigned Hitler to the same fate as Napoleon. Moscow was a marsh light that lured each would-be conqueror to his ultimate undoing.