Soviet Union

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| colspan="2" | ¹On 21 December 1991, eleven of the former socialist republics declared in Alma-Ata (with the 12th republic – Georgia – attending as an observer) that with the formation of the Commonwealth of Independent States the Union of Soviet Socialist Republics ceases to exist.
²Assigned on 19 September 1990, existing onwards.
³The governments of Estonia, Latvia, and Lithuania view themselves as continuous and unrelated to the respective Soviet republics.
Russia views the Estonian, Latvian, and Lithuanian SSRs as legal constituent republics of the USSR and predecessors of the modern Baltic states.
The Government of the United States and a number of other countries did not recognize the annexation of Estonia, Latvia, and Lithuania to the USSR as a legal inclusion. |-

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The Union of Soviet Socialist Republics (USSR, , abbreviated СССР, SSSR), informally known as the Soviet Union () or Soviet Russia, was a constitutionally socialist state that existed on the territory of most of the former Russian Empire in Eurasia between 1922 and 1991.^[1]

The Soviet Union had a single-party political system dominated by the Communist Party until 1990.^[2] Although the USSR was nominally a union of Soviet republics (of which there were 15 after 1956) with the capital in Moscow, it was in actuality a highly centralized state with a planned economy. Much of Soviet society was overseen by national security agencies such as the KGB (which was active from 1954).^[3]

The Soviet Union was founded in December 1922 when the Russian SFSR, which formed during the Russian Revolution of 1917 and emerged victorious in the ensuing Russian Civil War, unified with the Transcaucasian, Ukrainian and Belorussian SSRs. After the death of Vladimir Lenin, the first Soviet leader, power was eventually consolidated by Joseph Stalin,^[4] who led the country through a large-scale industrialization with command economy and political repression.^[4][5] During World War II, in June 1941, the Soviet Union was attacked by Germany, a country with whom it had signed a non-aggression pact. After four years of warfare, the Soviet Union emerged as one of the world's two superpowers, extending its influence into much of Eastern Europe and beyond.

The Soviet Union and its satellites from the Eastern Bloc were one of two participating factions in the Cold War, a global ideological and political struggle against the United States and its allies; the Soviet bloc ultimately lost, however, having been hit by economic standstill and both domestic and foreign political unrest, an event which marks the beginning of the post-war period.^[6][7] In the late 1980s the last Soviet leader Mikhail Gorbachev tried to reform the state with his policies of perestroika and glasnost, but the Soviet Union collapsed and was formally dissolved in December 1991 after the abortive August coup attempt.^[8] Since then the Russian Federation has been exercising its rights and fulfilling its obligations.^[9]

Geography, climate and environment

The Soviet Union at its maximum size in 1991, with ,^[10] was the world's largest state. Covering a sixth of the world's inhabited land, its size was comparable to that of North America. The western part (in Europe) accounted for a quarter of the country's area, and was the country's cultural and economic center. The eastern part (in Asia) extended to the Pacific Ocean to the east and Afghanistan to the south, and was much less populated than the European part. It was over across (11 time zones) and almost north to south.^[11] Its five climatic zones were tundra, taiga, steppes, desert, and mountains.

The Soviet Union had the world's longest border, measuring over .^[when?] Two thirds of the Soviet border was coastline of the Arctic Ocean. Across the Bering Strait was the United States. The Soviet Union bordered Afghanistan, China, Czechoslovakia, Finland, Hungary, Iran, Mongolia, North Korea, Norway, Poland, Romania, and Turkey at the end of WWII.

The Soviet Union's longest river was the Irtysh. The Soviet Union's highest mountain was Communism Peak (today's Ismail Samani Peak) in Tajikistan at . The world's largest lake, the Caspian Sea, lay mainly in the Soviet Union. The world's deepest lake, Lake Baikal, was in the Soviet Union.

History

The last Russian Tsar, Nicholas II, ruled until March 1917, when the Russian Empire was overthrown and a short-lived Russian provisional government took power, to be overthrown in November 1917 by Vladimir Lenin.

From 1917 to 1922, the predecessor to the Soviet Union was the Russian Soviet Federative Socialist Republic (RSFSR), which was an independent country, as were other Soviet republics at the time. The Soviet Union was officially established in December 1922 as the union of the Russian (colloquially known as Bolshevist Russia), Ukrainian, Belarusian, and Transcaucasian Soviet republics ruled by Bolshevik parties.

Revolution and the foundation of a Soviet state

Modern revolutionary activity in the Russian Empire began with the Decembrist Revolt of 1825, and although serfdom was abolished in 1861, its abolition was achieved on terms unfavorable to the peasants and served to encourage revolutionaries. A parliament—the State Duma—was established in 1906 after the Russian Revolution of 1905, but the Tsar resisted attempts to move from absolute to constitutional monarchy. Social unrest continued and was aggravated during World War I by military defeat and food shortages in major cities.

A spontaneous popular uprising in Saint Petersburg, in response to the wartime decay of Russia's economy and morale, culminated in the "February Revolution" and the toppling of the imperial government in March 1917. The tsarist autocracy was replaced by the Provisional Government, whose leaders intended to conduct elections to Russian Constituent Assembly and to continue participating on the side of the Entente in World War I.

At the same time, workers' councils, known as Soviets, sprang up across the country. The Bolsheviks, led by Vladimir Lenin, pushed for socialist revolution in the Soviets and on the streets. In November 1917, during the "October Revolution", they seized power from the Provisional Government. In December, the Bolsheviks signed an armistice with the Central Powers. But, by February 1918, fighting had resumed. In March, the Soviets quit the war for good and signed the Treaty of Brest-Litovsk.

Only after the long and bloody Russian Civil War was the new Soviet power secure. The civil war between the Reds and the Whites started in 1917 and ended in 1923. It included foreign intervention, the execution of Nicholas II and his family and the famine of 1921, which killed about 5 million.^[12] In March 1921, during a related conflict with Poland, the Peace of Riga was signed and split disputed territories in Belarus and Ukraine between the Republic of Poland and Soviet Russia. The Soviet Union had to resolve similar conflicts with the newly established Republic of Finland, the Republic of Estonia, the Republic of Latvia, and the Republic of Lithuania.