But even as the last opposition to Stalin disappeared on the domestic front, a new force was rising to challenge him in the heart of Europe. Adolf Hitler, had taken power in Germany in 1933--in part by playing on anti-Communist feeling--and Hitler's magnum opus, Mein Kampf, had pledged Germany to the destruction of the inferior Russian Slavs and the conquest of Lebensraum ("living space") in the Russian East.
Throughout the '30s, the Nazis and the Soviets seemed on a collision course, as Hitler denounced the "Bolshevik Menace" and the two nations fought a proxy war in Spain, each supporting a different side in that country's civil war. For a time, Stalin considered an alliance with the western Allies, France and Britain, in order to contain the growing Nazi threat; indeed, his Commissar for Foreign Affairs, Maxim Litvinov, publicly proposed such an alliance in 1935. That offer remained on the table, however, until 1938, by which point Hitler had conquered Czechoslovakia and Austria, and seemed ready to swallow up Poland as well. By now, although Stalin still desired to contain Hitler, allying with France and England in defense of the Poles would have meant war, which the Soviet leader wished to avoid at all costs. Moreover, he had become unfavorably impressed with the tactics of the western powers, whose policy of appeasement had done little to contain Hitler. He replaced Litvinov with Vyacheslav Molotov, by now one of his top lieutenants, and Molotov carved out a pact with the German foreign minister, Joachim von Ribbentrop, by which Russia and Germany agreed not to attack one another. This sacrifice of ideology, signed in August of 1939, shocked and frightened the West--but it should have come as no surprise to anyone familiar with Stalin's political cunning. A month later, Germany invaded Poland, igniting the Second World War.