A struggle for leadership followed Lenin's death in early 1924; Joseph V. Stalin and Leon Trotsky were the two main protagonists, with Stalin emerging victorious by the late 1920s. Stalin's program called for a more gradual transformation of Soviet society than did Trotsky's and had as its primary objective the consolidation of communism in the USSR rather than Trotsky's ideal of immediate world revolution. Later Stalin adopted more radical measures. Nevertheless, the Soviet Union continued to guide the Communist parties abroad through the Third International, or Comintern.The First Five-Year Plan
At home the New Economic Policy instituted in 1921 was replaced by full government planning with the adoption of the first Five-Year Plan (1928–32). The plan was drawn up by Gosplan (the state planning commission), setting goals and priorities for virtually the entire economy and emphasizing the production of capital and not consumer goods. A system of collective and state farms was imposed over widespread peasant opposition, which was expressed notably in the slaughter of livestock. Those comparatively prosperous peasants (called kulaks) who refused to join the new agricultural institutions were "liquidated" by drastic means. More than 5 million peasant households were eliminated, their property was confiscated, and most of the peasants were sent as forced laborers to Siberia. This also led to famine in 1932–33. By the end of the 1930s, 99% of the cultivated land was in collective farms (the system of state farms was established successfully only after World War II). Industrialization was accelerated, and the production of desperately needed industrial raw materials and capital equipment was stressed at the expense of consumer goods. One of the major results of the successive Five-Year Plans was the spectacular industrial and agricultural development of the Urals, Siberian USSR, and Central Asian USSR.
The level of literacy, very low in 1917, was steadily raised in all parts of the country, and free medical and social services were extended to the population. At the same time, the state (and behind it, the CPSU) increased its hold over all political, social, and cultural aspects of life. Education and media of public information passed under state control. Freedom of movement was severely restricted. All criticism of public policy, if not authorized by the state, was banned. The secret police became a major instrument of state control, and much power was given to the civil service. The system of controls gave rise to a large and powerful bureaucracy, called the "new class" by some analysts.
Religious bodies were severely persecuted in the early years of the Soviet Union, but in the mid-1930s there was a measure of relaxation in official policy, probably because antireligious propaganda in the schools had already taken effect among the younger generation. However, relations with the Roman Catholic Church and with the Jewish community remained hostile. Relations were also strained with the West Ukrainian Catholic Church and the Ukrainian Orthodox Church.
The mid-1930s saw a conservative trend in official attitudes toward culture: family life was emphasized again, and divorces and abortions were made difficult to obtain; great men and events in pre-1917 Russian history were extolled in literature (e.g., in works by Aleksey N. Tolstoy) and in films (especially those of Sergei Eisenstein); and experimentation in education gave way to a return to structure and discipline. In 1936 the Stalin constitution was issued, and it included many features of Western democracies, which, however, were more window-dressing than true indications of the distribution of power in the Soviet system.
The CPSU continued to control the government and run the country, and Stalin, as the Wisest of the Wise, was firmly in control of the party. Following the murder (1934) of Sergei M. Kirov, one of Stalin's closest associates, and the announcement of the discovery of an alleged plot against Stalin's regime headed by the exiled Trotsky, there began a series of purges that culminated in the great purge from 1936 to 1938. The armed forces, the CPSU, and the government in general were purged of all allegedly dissident persons; the victims were generally sentenced to death or to long terms of hard labor. Much of the purge was carried out in secret, and only a few cases were tried in public "show trials." Among the many thousand victims of the purges were such prominent CPSU leaders as Grigori E. Zinoviev, Lev B. Kamenev, Karl Radek, Nikolai Bukharin, and Aleksey I. Rykov and military figures like Marshal Mikhail N. Tukhachevsky. Independent influence in society was thus ended, and monolithic unity under Stalin was achieved by 1939.
Soviet foreign policy, long hampered by the hostility of the nations of Europe and America and by pervasive mutual distrust, was carried out first by Georgi Chicherin and from 1930 by Maxim M. Litvinov. In 1933 the United States recognized the USSR, and in 1934 the Soviet Union was admitted into the League of Nations. In the mid-1930s the USSR sought friendly relations with its neighbors, declared its renunciation of imperialistic expansion, and advocated total disarmament. Soviet-controlled Communist parties in other countries became friendlier to more moderate socialists and to liberals and in 1936 joined leftist Popular Front coalitions in France and Spain. The Western nations did not invite the USSR to take part in the negotiations with Germany leading to the Munich Pact (1938), and a radical shift in Soviet foreign policy ensued. V. M. Molotov replaced Litvinov as foreign minister.
On Aug. 23, 1939, the USSR concluded a nonaggression pact with Nazi Germany, which shortly afterward invaded Poland, precipitating World War II. Soviet troops also entered (Sept., 1939) Poland, which was divided between Germany and the USSR. Lithuania, Latvia, and Estonia were occupied (1940) by the Soviet Union, and in mid-1940 were transformed into constituent republics of the USSR. Finland opposed Soviet demands, and the Finnish-Russian War of 1939–40 resulted; it ended in a hard-earned Soviet victory. Finland ceded territory, which was organized into the Karelo-Finnish SSR (which in 1956 became part of the RSFSR as the Karelian Autonomous Soviet Socialist Republic). Romania was forced (1940) to cede Bessarabia and N Bukovina, and the Moldavian SSR was created. In Apr., 1941, a nonaggression treaty with Japan was signed.
Although defense preparations were accelerated (probably in anticipation of eventual war with Germany), when Germany attacked on June 22, 1941, the Soviet Union was caught by surprise. Romania, Finland, Hungary, Slovakia, and Italy joined in the invasion of the USSR. By the end of 1941 the Germans had overrun Belorussia and most of Ukraine, had surrounded Leningrad (St. Petersburg), and were converging on Moscow. The success of this first German offensive was in part due to the 1935–39 purges of the army and the party, which had robbed the USSR of many of its best military minds and political organizers.
A Soviet counter-offensive saved Moscow, but in June, 1942, the Germans launched a new drive directed against Stalingrad (now called Volgograd) and the Caucasus petroleum fields. Stalingrad held out, and the surrender (Feb. 2, 1943) of 330,000 Axis troops there marked a turning point in the war. The Soviets drove the invaders back in an almost uninterrupted offensive and in 1944 entered Poland and the Balkan Peninsula. Early in 1945, German resistance in Hungary was overcome, and Soviet troops marched into East Prussia. The converging Soviet armies then closed in on Berlin in a climactic drive. On May 2, 1945, Berlin fell; on May 7 the USSR together with the Western Allies accepted the surrender of Germany.
The Soviet victory was obtained at the great price of at least 20 million lives (including civilian casualties) and staggering material losses. The United States contributed much aid, about $9 billion, to the USSR through lend-lease. Understandings concerning the conduct of war and postwar policies had been reached by the USSR, the United States, and Great Britain at the Moscow Conferences (1941–47), the Tehran Conference (1943), the Yalta Conference (1945), and the Potsdam Conference (1945).
In accordance with a previous agreement, the Soviet Union declared war on Japan on Aug. 8, 1945, two days after the United States dropped an atomic bomb on Hiroshima. A swift campaign brought Soviet forces deep into Manchuria and Korea by the date (Sept. 2, 1945) Japan surrendered. As a direct result of the war, the USSR received the southern half of Sakhalin Island and the Kuril Islands from Japan; the northern part of East Prussia from Germany; and some additional territory from Finland. By agreements in 1945 with Poland and Czechoslovakia the USSR also vastly increased the area of the Belorussian and Ukrainian republics.
Cooperation between the USSR and the Western powers—already shaky during the war—ceased soon after the armistice, and relations between the Soviet Union and the United States (which emerged from the war as the two chief powers in the world) became increasingly strained, leading to the international tension of the cold war. Friction became particularly acute in the jointly occupied countries of Germany, Austria, and Korea and in the United Nations (of which the USSR was a charter member), preventing the conclusion of joint peace treaties with Germany, Austria, and Korea and agreements over reparations and the control of nuclear weapons.
Increasing Soviet influence in Poland, Czechoslovakia, Hungary, Romania, Bulgaria, and Albania and the continued tight control of East Germany created fears in the Western world of unlimited Soviet expansion, as did the creation (1947) of the Cominform (which in a limited sense was the successor of the Comintern). The USSR, on the other hand, justified its policies by claiming that it was merely responding to encirclement by hostile capitalist nations. In 1948, Yugoslavia declared its independence from the "Soviet bloc," as the Communist nations of East Europe came to be known. In 1948 and 1949 the USSR unsuccessfully tried to prevent supplies from reaching the sectors of Berlin occupied by the Western Allies. In 1949, the USSR recognized the newly established Communist government of China, and a 30-year alliance was signed in early 1950. Relations with the Western powers worsened considerably after the outbreak of the Korean War (1950–53), which the West ascribed to Soviet instigation.
Internally, the goals of the immediate postwar era were the reconstruction of the Soviet economy and the reimposition of Stalin's dictatorship. A fourth Five-Year Plan was released, concentrating as usual on heavy industrial development, which had shifted east due to the war. Despite impressive developments in industry, Soviet agriculture suffered greatly in the postwar period, as a drought in 1946 caused a massive famine. Collective farming proved once again to be hugely inefficient. The development of military technology continued rapidly, however, and the Soviet Union exploded its first atomic device in 1949.
Stalin managed to reassert his personal rule once more, ending the period of relatively free interaction in Soviet society mandated by the war effort. Millions of soldiers and ethnic minorities who had come into contact with the Germans and the Allies were deported to Central Asia and Siberia. Stalin instituted another round of anti-Semitic purges, killing many prominent Jewish writers. Propaganda extolling Communism's achievements reached new heights, as the government claimed Russian origins for nearly everything, even the American pastime of baseball.