As a Marxist–Leninist, Stalin expected an inevitable Second World War between competing capitalist powers; as Nazi Germany annexed Austria and then part of Czechoslovakia in 1938, Stalin recognized that this war was looming. He sought to maintain Soviet neutrality in the conflict, hoping that a German war against France and the UK would leave the Soviets a dominant force in Europe.[422] Militarily, the Soviets also faced a threat from the east, with Soviet troops clashing with the expansionist Japanese in the latter part of 1930. Stalin initiated a military build-up, with the Red Army more than doubling between January 1939 and June 1941, although in its haste to expand many of its officers were poorly trained.
As Britain and France seemed unwilling to commit to an alliance with the Soviet Union, Stalin saw a good deal with the Germans. In May 1939, Germany started negotiations with the Soviets, proposing that Eastern Europe be divided between the two powers. Stalin saw this as an opportunity both for territorial expansion and brief peace with Germany. In August 1939, the Soviet Union signed a nonviolence pact with Germany, negotiated by Soviet foreign minister Molotov and German foreign minister Ribbentrop. A week later, Germany invaded Poland, sparking the UK and France to declare war on it. On 17 September, the Red Army entered eastern Poland, officially to restore order amid the collapse of the Polish state; this explanation was also designed so as not to infuriate the UK and France.
Stalin suggested a territorial exchange with Germany, giving them the ethnic Polish-dominated areas and part of Warsaw Province, and in return receiving Lithuania; Stalin had desired the reintegration of the three Baltic states into the Soviet Union. This was agreed in 28 September. A German–Soviet Frontier Treaty was signed shortly after, in Stalin's presence. The two nations continued trading, undermining the British blockade of Germany.
The Red Army entered the Baltic states, which were forcibly merged into the Soviet Union in August. The Soviets also claimed Finland, but the Finnish government refused their demands. The Soviets invaded Finland in November; despite their numerical inferiority, the Finns kept the Red Army at bay. International opinion backed Finland, with the Soviets being expelled from the League of Nations.Embarrassed by their inability to defeat the Finns, the Soviets signed an interim peace treaty, in which they received territorial concessions from Finland. In June 1940, Romania was also annexed into the Soviet Union. The Soviet authorities sought to forestall any dissent in these new East European territories. The most noted instances was the massacre of April and May 1940, in which 22,000 members of the Polish armed forces, police, and intelligentsia were executed.
The speed of the German victory over and occupation of France in summer 1940 took Stalin by surprise. He increasingly focused on appeasement with Germany to delay any conflict with them. After the Tripartite Pact was signed by Axis Powers Germany, Japan and Italy, in October 1940, Stalin approached Germany with the suggestion that it too join the Axis alliance. To demonstrate peaceful intentions toward Germany, in April 1941 the Soviets signed a neutrality pact with Japan. On 6 May, Stalin replaced Molotov as Premier of the Soviet Union. Although head of government for 15 years, Stalin concluded that relations with Germany had deteriorated to such an extent that he had to deal with the problem.
