In later years Transcaucasia was divided into the Georgian, Armenian, and Azerbaijan Soviet Socialist republics; Kazakhstan and Central Asia were separated from the Russian SFSR; and Central Asia was divided into the Turkmen, Uzbek, Tadzhik, and Kirgiz Soviet Socialist republics.

By 1924 the major world powers, having initially attempted to isolate the Soviet government, had established diplomatic relations with it, and the Soviet Union was taking part in international conferences. The United States, the last major power withholding recognition, formally recognized the Soviet government in 1933, during the administration of President Franklin D. Roosevelt.

Economic Transformation

By 1927 the New Economic Policy devised by Lenin, under which a certain measure of capitalism was permitted, had brought about sufficient recovery to warrant an effort to renew the drive towards socialism in accordance with long-range Soviet objectives. Accordingly, a new period of planned economy began in 1928 with the inauguration of the first of the Stalin's Five-year plans. The basic aims of the Five-year plans were to convert the USSR from a backward agricultural country to a leading industrial power, to effect the complete collectivization of agriculture, and to transform the very nature of society.

The Great Purge

Politically, the mid-1930s were marked by a drastic purge from the Communist party and the government of all elements alleged to be in opposition to the policies of Stalin. The purge was touched off by the assassination in December 1934 of Sergey M. Kirov, a supporter of Stalin and member of the party. Between 1935 and 1939 Stalin had all those suspected of opposition removed from posts of authority; many were imprisoned, exiled to Siberia, or executed. Indeed, between 1934 and 1938 two-thirds of the members of the 1934 Central Committee were sentenced and executed. More than half of the high-ranking army officers were purged between 1936 and 1938.

In a series of spectacular trials held in Moscow between 1936 and 1938, several of the most prominent party leaders, including Grigory Y. Zinovyev, Bukharin, and Rykov, were accused, convicted, and executed for allegedly conspiring with Germany and Japan to overthrow the Soviet government. In a separate, secret trial, several commanders of the Red Army, including Marshal Mikhail N. Tukhachevsky, were convicted on similar charges and executed. The trials aroused worldwide condemnation of the Soviet system, which was seriously weakened by these great losses.

Foreign Affairs

In Moscow's view, international events in the 1930s increasingly endangered the security of the USSR. In the Far East, Japan occupied Manchuria in 1931, and friction gradually mounted between the Japanese occupation armies and the Soviet forces stationed along the Manchurian border. In 1938 the previously sporadic armed clashes developed into serious border warfare.