The most horrendous event in the history of the Soviet Union was World War II. The German armies were responsible for the deaths of 25 million Soviets; they also left another 25 million homeless and destroyed an untold number of farms and factories in their invasion of the USSR. It is a testimony to the remarkable power of communism's ability to work that the Soviet Union emerged from the war as one of the two most powerful nations in the world.

Given Stalin's dread of the West, and his conviction that the West was destined to invade Russia again, it is surprising that he did not see the danger that Nazi Germany posed to the Soviet Union. Even though the two nations had just collaborated on a partition of Poland and were parties to a mutual non-aggression pact, by 1941 the signs of a pending German invasion were obvious...