In Moscow’s Kremlin late on August 23, 1939, Soviet dictator Josef Stalin stood in the background beaming proudly as his foreign minister, Vyacheslav Molotov, and German dictator Adolf Hitler’s Reich minister for foreign affairs, Joachim von Ribbentrop, signed the Treaty of Non-Aggression between Germany and the USSR. Known variously as the Nazi-Soviet Pact, the Hitler-Stalin Pact, and the Molotov-Ribbentrop Pact, this notorious treaty negotiated by the two cynical dictators was in reality a death sentence for millions, as it paved the way for World War II in Europe. This sudden, unexpected rapprochement between two seemingly implacable enemies – Nazi Germany and the communist Soviet Union – not only shocked leaders throughout Europe and the world, it also sent Hitler’s and Stalin’s propagandists into frenzied efforts. They now had to portray as “friends” the countries and political systems they had demonized for years. In addition to the treaty’s main provision of guaranteeing neutrality if either side went to war against a third nation, the pact contained secret protocols dividing Eastern European countries (Poland, Romania, Estonia, Latvia, Lithuania and Finland) into German and Soviet spheres of influence. On September 1, only nine days after the document was signed, Hitler launched the invasion of Poland – precipitating the beginning of World War II in Europe when Britain and France responded September 3 by declaring war on Germany. In accordance with the pact’s secret protocols, Stalin’s Red Army invaded and occupied eastern Poland September 17. Historians typically emphasize the advantages Hitler gained in the pact, in that it transformed potential Soviet interference during the Poland invasion into active cooperation. Yet decisions made by both Hitler and Stalin led to the creation of the most cynical – and deadly – treaty in history. Hitler, history’s most notorious political predator, decided to seek the Nazi-Soviet Pact for the apparent immediate advantages it promised. Despite the Western Allies’ wartime propaganda claim that Hitler had a “master plan” for world dominance, he seldom thought more than one move ahead, preferring instead to rely on his “instincts” to guide his typically spontaneous actions. The German dictator assumed that Britain and France, faced with a Soviet Union neutralized by the pact, would permit his armies to conquer Poland as they had meekly acquiesced to his 1938 occupation of Czechoslovakia. Another major factor in Hitler’s decision to seek a treaty with Stalin was his desire for a trade agreement between Germany and the USSR. Millions of tons of Russian grain, oil and other vital war materials otherwise unobtainable by Germany were promised (and were scrupulously delivered by Stalin) in exchange for German technical equipment and assistance. Hitler correctly judged that these huge stockpiles of Soviet goods would be a hedge against a British naval blockade if war erupted. Finally, despite the pact’s secret protocols giving Stalin a free hand in extending Soviet influence into Eastern Europe, Hitler was convinced he could quickly overrun these gains when he eventually turned his German armies toward conquering the USSR. Although Stalin’s decision to agree to the pact with Hitler shocked world leaders at the time, in retrospect his strategy was sound. The Soviet dictator was unimpressed with Britain’s and France’s lukewarm attempts at forging an anti-Hitler alliance with the USSR and assumed the two countries merely wanted his Red Army to fight Germany for them if war came – and undoubtedly he was right. Additionally, the pact’s secret protocols guaranteed that Germany would not interfere with Soviet territorial ambitions in Eastern Europe (the Baltic nations, eastern Romania and Finland) and would hand the USSR eastern Poland virtually without a fight. Furthermore, the pact would protect European Russia from a German threat while the Red Army secured its Far East border with Japan. The Soviet vs. Japanese Battle of Khalkin Gol (May-September 1939) on the Manchukuo-Mongolian border was still playing out as the pact was being negotiated. General Georgi Zhukov’s Red Army victory at Khalkin Gol eventually led to the vitally important April 1941 USSR-Japan Non-Aggression Treaty that postponed all-out war with Japan until August 1945. Stalin’s decision to approve the Nazi-Soviet Pact may have been egregiously cynical, but it was brutally logical. Despite the dictators’ euphoria at forging the pact, both men made critical misjudgments. Hitler’s first miscalculation was assuming that Britain and France – seemingly cowed by the infamous Munich Agreement and then left bereft of any hope of assistance from the USSR in blocking Nazi aggression by the Nazi-Soviet Pact – would idly stand by as Germany overran Poland. Britain and France instead declared war on Germany. However, Hitler’s fatal misjudgment – at least in part the result of Stalin’s subsequent strict adherence to the pact’s provisions – was underestimating the Stalinist regime’s ruthless resolve and its surprising ability to mobilize the full fury of the Soviet people to oppose the German invasion that began June 22, 1941. That misjudgment prompted the greatest clash of arms in history, the fighting on World War II’s Eastern Front, and resulted in the catastrophic defeat of Hitler’s Nazi Germany in May 1945. Stalin’s misjudgments, meanwhile, proved to be more about duration and timing – serious, but not fatal to the USSR. Unlike Hitler, Stalin was not surprised by Britain’s and France’s declarations of war. In deed, he expected them. However, he incorrectly believed the belligerents would exhaust themselves in a prolonged struggle in Western Europe, leaving the Soviet Union as Europe’s most powerful country. Instead, Hitler’s western offensive that began in May 1940 defeated France in six weeks and left Britain battered and reeling. Stalin next miscalculated the timing of Hitler’s now-inevitable attack on the Soviet Union, incorrectly assuming Germany would finish off Britain before invading the USSR. He compounded this mistake by naively thinking he could delay the German attack by mollifying Hitler through strict adherence to the pact’s provisions and by prohibiting the Red Army from taking any actions to prepare for the invasion that might be misconstrued as a provocation. The result was a Red Army ill-prepared to oppose the June 1941 German juggernaut and staggering Soviet casualty lists in the Eastern Front’s initial battles. Yet with Japan held at bay by the 1941 Soviet-Japanese Neutrality Pact, the USSR fought only a one-front war against Germany. Perhaps as many as 30 million Soviet soldiers and citizens perished in the effort to achieve final victory – but it was a price in blood that Stalin was willing to pay.