On June 22, 1941, Hitler invaded the Soviet Union in Operation Barbarossa, one of the turning points of World War II. Within six months, the invasion bogged down at the gates of Moscow, and the Eastern Front proved to be the decisive theater in the defeat of the Third Reich. Ever since, most historians have agreed that this was one of Hitler's great mistakes. In Hitler's Great Gamble, James Ellman argues that Barbarossa was a gamble, but that it was not doomed from the start: that it was a reasonable gamble spoiled not by strategic shortsightedness, but by diplomatic setbacks and poor execution. In Ellman's recounting, the invasion of the Soviet Union was not a doomed act of madness or hubris, but a logical gamble that maximized the Third Reich's attempts at achieving its war aims, however perverted, of