German–Soviet Union relations date to the aftermath of the First World War. The Treaty of Brest-Litovsk, dictated by Germany ended hostilities between Russia and Germany; it was signed on March 3, 1918. A few months later, the German ambassador to Moscow, Wilhelm von Mirbach, was shot dead by Russian Left Socialist-Revolutionaries in an attempt to incite a new war between Russia and Germany. The entire Soviet embassy under Adolph Joffe was deported from Germany on November 6, 1918, for their active support of the German Revolution. Karl Radek also illegally supported communist subversive activities in Weimar Germany in 1919. From the outset, both states sought to overthrow the system that was established by the victors of World War I. Germany, laboring under onerous reparations and stung by the collective responsibility provisions of the Treaty of Versailles, was a defeated nation in turmoil. This and the Russian Civil War made both Germany and the Soviets into international outcasts, and their resulting rapprochement during the interbellum was a natural convergence. At the same time, the dynamics of their relationship was shaped by both a lack of trust and the respective governments' fears of its partner's breaking out of diplomatic isolation and turning towards the French Third Republic (which at the time was thought to possess the greatest military strength in Europe) and the Second Polish Republic, its ally. The countries' economic relationship dwindled in 1933, when Adolf Hitler came to power and created Nazi Germany; however, the relationships restarted in the end of 1930s, culminating with the Molotov–Ribbentrop Pact of 1939 and several trade agreements. Few questions concerning the causes of World War II are more controversial and ideologically loaded than the issue of the policies of the Soviet Union under Joseph Stalin towards Nazi Germany between the Nazi seizure of power and the German invasion of the USSR on June 22, 1941. A variety of competing and contradictory theses exist, including: that the Soviet leadership actively sought another great war in Europe to further weaken the capitalist nations; that the USSR pursued a purely defensive policy; or that the USSR tried to avoid becoming entangled in a war, both because Soviet leaders did not feel that they had the military capabilities to conduct strategic operations at that time, and to avoid, in paraphrasing Stalin's words to the 18th Party Congress on March 10, 1939, "pulling other nations' (the UK and France's)