Content Warning: This section contains descriptions of antisemitism and the Holocaust.

On June 22, 1941, Germany launched its invasion of the Soviet Union in what remains to this day the largest land action in military history. It would prove to be the most consequential decision in the 12-year history of the Nazi regime, as it would reach the height of its power on the European continent, building an empire that stretched from the English Channel to the gates of Moscow, only to then suffer grievous defeats which began a slow but ultimately total decline and fall. Historians have long debated why Adolf Hitler made this fateful choice, particularly given the circumstances of the moment. In the late summer of 1939, Hitler initiated World War II by avoiding the chief mistake Germany had made in World War I: fighting a two-front war. Prior to invading Poland, and thereby triggering war with France and Britain, Hitler made a pact with Soviet ruler Josef Stalin, essentially dividing Poland between them and ensuring Stalin’s cooperation as Germany focused on fighting its Western adversaries. The dark year of 1940 followed, culminating in the spectacular collapse of France, the near-destruction of the British expeditionary force (until its miraculous rescue at Dunkirk), and the commencement of the German blitz bombing of London and other British cities.