Ian Ona Johnson, "Faustian Bargain: The Soviet-German Partnership and the Origins of the Second World War" (Oxford UP, 2021)

German Ambassador Ulrich von Brockdorff-Rantzau believed that Germany and the Soviet Union were locked together in a Schicksalgemienshaft, or “community of fate.” The interaction of these two nations, Brockdorff-Rantzau thought, would decide the course of history, in Europe and beyond. Anyone familiar with the history of German-Soviet relations in the twentieth century might be inclined to agree with the ambassador’s assessment; though they might find his use of the word “community,” with all its positive connotations, somewhat out of place. For if the Germans and Soviets built any community at all, the evidence suggests it was not built on mutual respect and cooperation. Rather it was built on hate—vicious, unbridled, unrelenting hate. Hate, however, can unite as powerfully as it divides. Ideologically, politically, culturally, economically, and socially, the Germans and the Soviets were diametrically opposed. But for a brief period during the interwar years, their mutual hatred of the post-First World War order overcame their mutual distrust to bring these two powers together in an uncharacteristic, but highly consequential, economic, technologic, and military partnership. Formalized with the signing of the Treaty of Ropallo in April 1922, this uneasy alliance saw the Soviet Union provide a safe haven for German rearmament in return for German investment, trade, and military assistance. German officers, businessmen, industrialists, and engineers relocated to secret sites throughout the Soviet Union to work on the design of tanks and aircraft, develop new chemical weapons capabilities, and train a new generation of German military leaders away from the prying eyes of the Allied powers. Simultaneously, Soviet officers learned the art of war from their German counterparts, while their country acquired the industrial base, manufacturing expertise, and military hardware it believed necessary to advancing the Communist cause. Understanding the grave significance of that exchange is the object of military historian Ia