The Soviet Union was a federal socialist state that existed from 1922 to 1991, consisting of 15 socialist republics. The Soviet Union originated in the 1917 Russian Revolution, when radical leftist revolutionaries, the Bolsheviks, overthrew Czar Nicholas II and the centuries-old Romanov monarchy and a civil war followed. In 1922, a treaty between Russia, Ukraine, Belarus, and Transcaucasia (today’s Armenia, Azerbaijan, and Georgia) formed the Soviet Union, formally called the Union of Soviet Socialist Republics (USSR). From 1917 to 1991, the U.S.S.R. was comprised of 15 member states:
| Armenia | Azerbaijan | Belorussia (now Belarus) |
| Estonia | Georgia | Kazakhstan |
| Kirgiziya (now Kyrgyzstan) | Latvia | Lithuania |
| Moldavia (now Moldova) | Russia | Tajikistan |
| Turkmenistan | Ukraine | Uzbekistan |
The founding leader of the USSR’s newly established Communist Party was Vladimir Lenin. After Lenin died in 1924, Joseph Stalin rose to power and ruled until 1953. During his rule, Stalin transformed the Soviet Union into an industrial and military superpower. This came at a cost to the Soviet Union’s citizens, as Stalin ruled by terror, which left millions dead.
The Soviets signed a non-aggression treaty with Nazi Germany in 1939 after failing to form an alliance with Western powers. Despite an attempt to stay neutral, the Soviets were pressed by Germany to invade and annex territories of several Eastern European states early in World War II. These states included Poland and the Baltic states. However, German leader Adolf Hitler soon broke the agreement and attacked Russia, driving the Soviets to side with the Allies. After Soviet forces captured Berlin and the Allies won the war in Europe in 1945, the territory overtaken by the Soviet forces became satellite states of the Eastern Bloc. The Eastern bloc, or Communist bloc, refers to the group of states in central and Eastern Europe, East Asia, and Southeast Asia that were under the control of the Soviet Union. The Eastern Bloc existed from 1947 to 1991 in opposition to the capitalist, U.S.-led Western Bloc.
After World War II, relations between the USSR and the United States and Great Britain began to deteriorate. The USSR had established communist governments in multiple Eastern European countries, creating concern among Western countries regarding the spread of communism to the rest of the world. In 1949, the North Atlantic Treaty Organization (NATO) was formed by the U.S., Canada, and European allies as a force against the USSR.
The Soviets responded by consolidating power among Eastern bloc countries in 1955 under the Warsaw Pact. This sparked the Cold War, a decades-long exchange of political, economic, and propaganda attacks between the Eastern and Western blocs. The rivalry caused anti-communist suspicions and international events that almost led the United States and the Soviet Union to the edge of a nuclear war. The Cold War lasted until 1991, when the USSR fell.
During the 1960s and 1970s, the Soviet elites rapidly gained wealth and power while millions of citizens faced starvation and poverty. Citizens lacked basic necessities including clothing, shoes, and food, and long "breadlines" of people in need of government assistance were common. These unbalanced conditions caused outraged among younger Soviet citizens. Additionally, the USSR saw backlash from other nations, such as the United States. U.S. President Reagan isolated the Soviet Union’s economy and forced down oil prices, greatly decreasing the Union’s revenue.
Political revolutions in the Eastern Bloc began in Poland in 1989. This sparked other revolutions across Eastern European states, including the reuniting of East Germany and West Germany and the destruction of the Berlin Wall (official reunification was made on October 3, 1990). In the USSR, debates over how much power the central government should possess coincided with strong waves of nationalism among the various member states. Estonia became the first Soviet state to formally break away, declaring its sovereignty in November 1988 and formally seceding from the USSR in May 1990. Other states followed, and the USSR officially dissolved on December 31, 1991, breaking into more than a dozen individual republics.
Many of the former Soviet states faced significant issues following the dissolution of the USSR. Most formerly socialist nations struggled to transition to market economies, and their additional needs included attaining political stability, rebuilding industries, reversing population decline, and establishing or re-establishing official languages and religions. What's more, Russia, the remaining state, has sought to interfere with and even reclaim several former Soviet republics (Russia's 2022 invasion of Ukraine being a key example). Ultimately, many former Soviet states still face economic hardships and uncertain political futures.