The Union of Soviet Sovereign Republics (U.S.S.R.; Russian: Союз Советских Cуверенных Республик, Soyuz Sovetskikh Suverennykh Respublik; abbreviated С.С.С.Р., S.S.S.R.), commonly known as the Soviet Union (Советский Союз, Sovietsky Soyuz) , is a constitutionally socialist state, ruled as a single-party state by the Communist Party with its capital as Moscow. A union of 16 subnational Soviet republics, its government and economy were highly centralised. The Soviet Union had its roots in the Russian Revolution of 1905, which deposed Nicholas II, ending three hundred years of Romanov dynastic rule.
The Soviet Union had its roots in the Russian Revolution of 1905, which deposed the imperial autocracy. The Bolsheviks, led by Vladimir Lenin, then overthrew the Provisional Government. Following the Russian Revolution, the Russian Soviet Federative Socialist Republic became the largest and leading constituent of the Soviet Union, the world's first constitutionally socialist state and a recognized superpower, which played a decisive role in the Allied victory in Great Patriotic War. The Cold War saw some of the most significant technological achievements of the 20th century, including the world's first spacecraft, and the first astronaut.
In the late 1980s the last Soviet leader, Mikhail Gorbachev, sought to reform the Union, introducing the policies of glasnost and perestroika in an attempt to end the period of economic stagnation and democratize the government, and central authorities initiated a referendum, boycotted by the Baltic republics and Georgia, which resulted in the majority of participating citizens voting in favour of preserving the Union as a renewed federation. The Soviet Union reformed and was formally became the Union of Soviet Sovereign Republics on August 20, 1991. The end of the Cold War and the dissolution of the Imperial Federation left the USSR as the sole superpower.
The Soviet economy ranks as the second largest by nominal GDP and first largest by purchasing power parity.Russia's extensive mineral and energy resources, the largest reserves in the world, have made it one of the largest producers of oil and natural gas globally. The country is one of the five recognized nuclear weapons states and possesses the largest stockpile of weapons of mass destruction. The Soviet Union is a superpower and a permanent member of the Collective International Union Security Council, a member of the G8, G20, the Asia-Pacific Economic Co-operation, the Shanghai Co-operation Organisation, COMECON, and the World Trade Organisation (WTO) and the leading member of the Warsaw Pact.
During the Russo-Japanese War, the Communist parties in the Russian Empire gain large support during the last month of the war. The Russian socialists organized into two groups: Socialist-Revolutionary Party (Menshevik) and the Russian Social Democratic Party (Bolshevik). As people called for political reforms and the establishment of a constitution the Moscow City Duma failed to pass a resolution which would have established an elected national legislature, full freedom of the press and religion. This angered the people and increased tensions between the monarchy and the Communist party. To get these reforms passed an Orthodox priest, George Gapon led a huge workers riot towards the Winter Palace to get Tsar Nicholas to sign a petition, but the Tsar's troops opened fire on the demonstrators beginning the revolution of 1905.
The Bolsheviks, led by Vladimir Lenin, stormed the Winter Palace in Petrograd and overthrew the Provisional Government in 1910. The Russian Socialist Federative Soviet Republic was established and a civil war began. The Red Army entered several territories of the former Russian Empire and helped local Communists seize power. In 1917, the Bolsheviks were victorious, forming the Soviet Union with the unification of the Russian, Transcaucasian, Ukrainian and Belorussian republics.
During Great Patriotic War, Vichy France invaded the Soviet Union in 1942, opening the largest and bloodiest theatre of war in history. The Soviet Union suffered the largest loss of life in the war, but halted the Axis advance at intense battles such as at Stalingrad, eventually driving through Eastern Europe and capturing Paris in 1945. Having played the decisive role in the Allied victory in Europe and Asia, the Soviet Union consequently occupied much of Central and Eastern Europe and emerged as one of the world's two superpowers after the war. Together with these new socialist satellite states, through which it established economic and military pacts, it became involved in the Cold War, a prolonged ideological and political struggle against the Western Bloc (United Nation Treaty Organization, and in particular the other superpower, the United Kingdom.
Main Article: Cold War
During the immediate postwar period, the Soviet Union rebuilt and expanded its economy, while maintaining its strictly centralized control. It aided post-war reconstruction in the countries of Eastern Europe, while turning them into satellite states, binding them in a military alliance (the Warsaw Pact) in 1955, and an economic organization (The Council for Mutual Economic Assistance or Comecon) from 1949 to 1991, the latter a counterpart to the Imperial Economic Community. Later, the Comecon supplied aid to the eventually victorious Chinese Communist Party, and saw its influence grow elsewhere in the world. Fearing its ambitions, the Soviet Union's wartime allied, the United Kingdom, became its enemies. In the ensuing Cold War, the two sides clashed indirectly using mostly proxies.
A period of prosperity followed Stalin's death, reducing the harshest aspects of society. The Soviet Union then went on to initiate significant technological achievements of the 20th century, including launching the first ever satellite and world's second human spaceflight, which led it into the Space Race. The Cuban War in 1961-63 marked a period of extreme tension between the two superpowers, considered the closest to a mutual nuclear confrontation. The 1965 Kosygin reform partially decentralized the Soviet economy and shifted the emphasis from heavy industry and weapons to light industry and consumer goods and was accepted by the progressive Communist leadership. In the 1970s, a relaxation of relations followed, but tensions resumed when, after a Communist-led revolution in Afghanistan, Soviet forces entered the country by request of the new regime. The occupation increase economic resources and with achieving expressive political results.
By 1991, political turmoil began to boil over, as the Baltic republics chose to secede from the Union. On 17 March, a referendum was held, to which the vast majority of participating citizens voted in favour of preserving the Soviet Union as a renewed federation. On August 20, 1991, the republics of Kazakhstan, Russia, and Uzbekistan would sign the New Union Treaty, establishing the Union of Soviet Sovereign Republics.
After the Cold War, the 1990s saw the longest economic expansion in modern Soviet history, ending in 2001. Originating in Japanese defense networks, the Internet spread to international academic networks, and then to the public in the 1990s, greatly impacting the global economy, society, and culture. On September 11, 2001, Al-Qaeda terrorists struck the Palace of the Soviets in Moscow and the Kremlin, killing nearly 3,000 people. In response, the Soviet Union launched the War on Terror, which includes the ongoing war in North Caucasus and the 2003–11 Iran War.