History remembers the Soviets and the Nazis as bitter enemies whose conflict was the decisive clash of World War II. Yet Hitler and Stalin signed a treaty of nonaggression that lasted for nearly a third of the war, and that is key to understanding why the war evolved—and ended—the way it did. In The Devils’ Alliance, Roger Moorhouse explains how the two powers—though ideologically opposed—forged a brutally efficient partnership, exchanging raw materials and machinery and orchestrating the division of Poland and the Baltic States. Hundreds of thousands caught between Hitler and Stalin were killed or deported. But ironically, by sharing materiel and technological expertise during the Pact, the Nazis and Soviets made possible a far more bloody and protracted war than would have been otherwise conceivable. Combining comprehensive research with a gripping narrative, The Devils’ Alliance is the authoritative history of the Nazi-Soviet Pact—and a portrait of the people whose lives were irrevocably altered by the alliance.