The Soviet Union (short for the Union of Soviet Socialist Republics or USSR) was a single-party Marxist–Leninist state. ... It was the first country to declare itself socialist and build towards a communist society. It was a union of 14 Soviet socialist republics and one Soviet federative socialist republic (Russia).

**The Soviet Union: A Comprehensive Explanation**

The Soviet Union, officially known as the Union of Soviet Socialist Republics (USSR), was a socialist state that existed from 1922 to 1991. It was located in Eurasia and spanned eleven time zones, covering a vast territory from Eastern Europe to Northern Asia. The USSR was founded on the principles of Marxism-Leninism, a political ideology that advocated for the establishment of a socialist society through the dictatorship of the proletariat.

**Formation and Structure**
The Soviet Union was formed in 1922 after the Russian Revolution of 1917, which overthrew the Russian monarchy and led to the rise of the Bolshevik Party, led by Vladimir Lenin. Lenin's government, known as the Russian Soviet Federative Socialist Republic (RSFSR), eventually transformed into the USSR. The country was composed of fifteen Soviet republics, with the Russian Soviet Federative Socialist Republic being the largest and most influential.

**Political System**
The Soviet Union had a centralized political system, with the Communist Party of the Soviet Union (CPSU) holding absolute power. The CPSU controlled all aspects of the government, economy, and society. The supreme legislative body was the Supreme Soviet, which consisted of two chambers: the Soviet of the Union and the Soviet of Nationalities. However, these institutions were largely symbolic, as real power resided in the hands of the party elite.

**Economic Structure**
The Soviet Union practiced a command economy, where the means of production were owned and controlled by the state. The government planned and directed economic activities, determining production quotas, resource allocation, and pricing. The economy focused on heavy industry and collectivized agriculture, with the state owning large industrial enterprises and collective farms. However, the centralized planning and lack of market mechanisms led to inefficiencies and shortages.

**Disintegration Factors**
The disintegration of the Soviet Union can be attributed to various factors:

1. Economic Decline: The Soviet economy experienced stagnation and inefficiency, leading to a decline in living standards for the population.
2. Nationalism: Ethnic tensions and desires for independence grew stronger among the Soviet republics, fueled by a sense of national identity and a desire for self-governance.
3. Political Reforms: Mikhail Gorbachev's policies of glasnost (openness) and perestroika (restructuring) aimed to address the economic and political issues but inadvertently triggered political upheaval and demands for greater autonomy.
4. Baltic Independence Movements: The Baltic republics of Estonia, Latvia, and Lithuania were at the forefront of the independence movement, challenging the Soviet government's authority.
5. August Coup: In 1991, a group of hardline communist leaders attempted a coup against Gorbachev, but their failure weakened the central government and further fueled calls for independence.

**Conclusion**
In December 1991, the Soviet Union officially dissolved, leading to the emergence of fifteen independent nations. The disintegration of the USSR marked the end of the Cold War era and had far-reaching geopolitical consequences. The legacy of the Soviet Union continues to shape the political, economic, and social landscapes of the successor states.