With this new army in the background, Stalin and the Soviet leaders still had to confront an increasingly dangerous world situation. The most important consequences of the new situation created by Hitler and his allies were the new policies enunciated at Geneva by Litvinov and also a sharp turn in the strategy of the Comintern. At the Seventh Comintern Conference in 1935 the Bulgarian Communist leader Georgii Dimitrov announced the new policy: the Popular Front. The new policy abandoned the attacks on the Socialists as agents of the ruling class and the orientation toward revolution, putting in its place the demand for Communists to make an alliance with the Socialists and indeed any group opposed to fascism for the purpose of preventing the extension of fascist power. At the same time the Soviet state began to try to form alliances with Western powers, signing mutual aid pacts with France and Czechoslovakia in May of 1935. Soviet relations with Britain, however, remained poor, and Hitler was on the march: in 1936 he remilitarized the Rhineland to thundering silence from London and Paris. A few months later the Civil War broke out in Spain with General Francisco Franco’s revolt against the Republic, now governed by a popular front elected by the people. Soviet reaction was initially cautious, as they feared that overt aid to the Republic would provoke intervention by the Western powers on the side of the monarchist-fascist rebels. Hitler and Mussolini soon solved that problem, for their supplies of troops and munitions gave the Soviets an opening. Stalin also sent tanks, aircraft, and many officers to Spain through the dangerous waters of the Mediterranean. In Spain, Stalin and the Comintern followed the popular front strategy, the Spanish Communists being instructed that they were not to make revolution but to continue to ally with the Socialists and Liberals to support the Republic. The Spanish situation revealed the limits of that strategy, for Stalin also wanted the Communists to control things as much as possible and insisted on eliminating the Trotskyists and Anarchists, powerful especially in Barcelona. In the long run, neither the Popular Front strategy nor Soviet aid and interference made much difference. The Spanish Republic succumbed to brute force and was extinguished by the end of 1938.
The defeat of the Republic only increased the danger for the USSR. The lack of enthusiasm on the part of Western powers for the Spanish Republic only revealed – in Stalin’s mind – the increasing chances of his nightmare scenario, a four-power pact that included Britain, France, Germany, and Italy, which would be directed against the Soviet Union. And Hitler continued to move. In 1936–37 Germany, Japan, and Italy signed the “Anti-Comintern Pact,” forming the alliance that came to known as the Axis. In 1938, Hitler annexed Austria, again causing no reaction from Britain and France, and soon began to make demands on Czechoslovakia, the only power in Eastern Europe with a substantial and modern armed force. For the Soviets as well as Europe as a whole, this was a crisis.
Soviet actions were stymied by two factors. One was the generally pro-German policy of Poland, which controlled the corridors through which any Soviet aid to Czechoslovakia had to pass. The other factor was the suspicion on the part of the Western powers, especially Britain – both of the Soviet Union in general and the capacities of the Red Army in particular. The Soviet mutual assistance pacts with France and Czechoslovakia hinged on cooperation, which was not forthcoming from Paris. In the days leading up to the final crisis at Munich, the Soviets did actually begin to mobilize the Red Army in secret, but all was in vain. Chamberlain surrendered the Czechs to Hitler in what from the Soviet point of view was a four-power pact. Such a pact, in their view, must be directed against the Soviet Union.
In this situation the Soviet leadership, convinced that war was coming, moved to its other possible strategy, making a deal with Hitler. Off and on since 1933 the Soviets had put out feelers to Berlin, but nothing had come of them. Early in 1939 discussions with the Nazis suddenly became serious, and the attitudes in London and Paris propelled them forward. Though Chamberlain began to realize that Hitler was a threat, he was not willing to discuss a serious agreement with Stalin. In the summer of 1939 a British mission to Moscow explored the possibilities of cooperation, but when Commissar of Defense Voroshilov asked for specifics on military cooperation, the British could reply only that they had no instructions. The result was the German-Soviet pact of August 23, 1939, signed in Moscow by Ribbentrop and Molotov, now Litvinov’s replacement as Commissar of Foreign Affairs.
The pact unleashed Hitler to attack Poland, which brought declarations of war against Germany from Britain and France. The German invasion of Poland was so successful and so quick that Stalin was caught off-guard. He was also preoccupied with the Japanese probing attack on Mongolia at the end of August, thrown back at Khalkhin Gol by some hundred thousand Soviet troops. Though the pact implied a partition of Poland, it had not included any delimitation of frontiers. The Red Army hurriedly marched into the eastern territories of the Polish state inhabited mainly by Belorussians and Ukrainians, annexing the new territories to the respective Soviet republics. The Communists quickly established Soviet institutions and deported the Poles in the area. Most went to camps or as “special settlers” to Siberia and Kazakhstan, but the army officers, police, and other officials were executed in the camp at Katyn forest and elsewhere early in 1940.
The pact also put the Baltic states into the Soviet sphere of influence. Stalin moved quickly to assert control over the area, in the process awarding the city of Vilnius to Lithuania, a city then almost entirely Polish and Jewish in population. By 1940, control was sufficient that the three states were incorporated into the USSR as Soviet republics, after “popular assemblies” went through the ceremony of “requesting” incorporation. Stalin thought his western border was now secure except for one area: Finland.
The Finnish-Soviet border was the result of the internationalization of an internal border of the Russian empire. When Russia annexed Finland in 1809, the Karelian isthmus to the west of St. Petersburg had been part of the Russian Empire for a hundred years, but in a concession to the Finns, was reunited with the rest of Finland. By 1918, at the time of Finnish independence, this meant that the border was only a short tram ride away from the center of Petrograd. The border had been a problem for Soviet military planners ever since, and Stalin decide to fix it. He proposed to the Finnish government a deal, giving the USSR control of strategic islands near the coast and moving the border some kilometers west in return for territory in the far north. The Finns decided that this was a ploy to take control of the country and refused. Thus began the Winter War, in which the small but well-trained and enthusiastic Finnish army held off the Soviets for several months, eliciting support from Britain and other Western powers that allowed them to draw public attention from the “phony war” along Germany’s western boundary. After many setbacks and heavy casualties, the Soviets finally got their army together and defeated the Finns, leaving an impression of incompetence that only encouraged their future enemies in Berlin. In the wake of the war, Stalin replaced the Commissar of Defense, his old Civil War crony Voroshilov, with S. T. Timoshenko, a professional military officer who quickly proceeded to reform the army and speed up its re-equipment.