signing the Treaty of Brest-Litovsk that concluded hostilities with the Central Powers of World War I; Bolshevist Russia surrendered most of its western territories, which hosted 34% of its population, 54% of its industries, 32% of its agricultural land, and roughly 90% of its coal mines. The Allied powers launched an unsuccessful military intervention in support of anti-communist forces. In the meantime, both the Bolsheviks and White movement carried out campaigns of deportations and executions against each other, known respectively as the Red Terror and White Terror. By the end of the violent civil war, Russia's economy and infrastructure were heavily damaged, and as many as 10 million perished during the war, mostly civilians. Millions became White émigrés, and the Russian famine of 1921–1922 claimed up to five million victims. Soviet Union On 30 December 1922, Lenin and his aides formed the Soviet Union, by joining the Russian SFSR into a single state with the Byelorussian, Transcaucasian, and Ukrainian republics. Eventually internal border changes and annexations during World War II created a union of 15 republics; the largest in size and population being the Russian SFSR, which dominated the union for its entire history politically, culturally, and economically. Following Lenin's death in 1924, a troika was designated to take charge. Eventually Joseph Stalin, the General Secretary of the Communist Party, managed to suppress all opposition factions and consolidate power in his hands to become the country's dictator by the 1930s. Leon Trotsky, the main proponent of world revolution, was exiled from the Soviet Union in 1929, and Stalin's idea of Socialism in One Country became the official line. The continued internal struggle in the Bolshevik party culminated in the Great Purge. Under Stalin's leadership, the government launched a command economy, industrialisation of the largely rural country, and collectivisation of its agriculture. During this period of rapid economic and social change, millions of people were sent to penal labor camps, including many political convicts for their suspected or real opposition to Stalin's rule; and millions were deported and exiled to remote areas of the Soviet Union. The transitional disorganisation of the country's agriculture, combined with the harsh state policies and a drought, led to the Soviet famine of 1932–1933; which killed up to 8.7 million, 3.3 million of them in the Russian SFSR. The Soviet Union, ultimately, made the costly transformation from a largely agrarian economy to a major industrial powerhouse