The Armenian Soviet Socialist Republic (Armenian SSR; Armenian: Հայկական Սովետական Սոցիալիստական Հանրապետություն Haykakan Sovetakan Soc'ialistakan Hanrapetut'yun; Russian: Армя́нская Сове́тская Социалисти́ческая Респу́блика Armyanskaya Sovetskaya Sotsialističeskaya Respublika) was one of the constituent republics of the Soviet Union in December 1922. It was established in December 1920, when the Soviets took over control of the short-lived First Republic of Armenia and lasted until 1991. It is sometimes called the Second Republic of Armenia, following the First Republic of Armenia's demise.
As part of the Soviet Union, the Armenian SSR transformed from a largely agricultural hinterland to an important industrial production center, while its population almost quadrupled from around 880,000 in 1926 to 3.3 million in 1989 due to natural growth and large-scale influx of Armenian Genocide survivors and their descendants. On August 23, 1990, it was renamed the Republic of Armenia, but remained in the Soviet Union until its official proclamation of independence on 21 September 1991. After the dissolution of the Soviet Union, the state of the post-Union Republic of Armenia existed until the adoption of the new constitution in 1995.
The Republics of the Soviet Union or the Union Republics (Russian: союзные республики, soyuznye respubliki) of the Soviet Union were ethnically based administrative units that were subordinated directly to the Government of the Soviet Union. For most of its history, the Soviet Union was a highly centralized state; the decentralization reforms during the era of Perestroika ("Restructuring") and Glasnost ("Openness") conducted by Mikhail Gorbachev led to the dissolution of the Soviet Union in 1991.
According to the Article 76 of the Constitution of the Soviet Union, a Union Republic was a sovereign Soviet socialist state that had united with other Soviet Republics in the Union of Soviet Socialist Republics. Article 81 of the Constitution stated that "the sovereign rights of Union Republics shall be safeguarded by the USSR".
In the final decades of its existence, the Soviet Union officially consisted of fifteen Soviet Socialist Republics (SSRs). All of them, with the exception of the Russian Federation (until 1990), had their own local party chapters of the All-Union Communist Party.
A socialist state or socialist republic (sometimes Workers' State) refers to any state that is constitutionally dedicated to the establishment of socialism. In Western usage, the term "Communist state" is often used in reference to single-party socialist states governed by parties adhering to a variant of Marxist-Leninism; however these states officially refer to themselves as "socialist states" that are in the process of building socialism and do not describe themselves as "communist" or as having achieved communism. Aside from the "Communist states", a number of other states have described their orientation as "socialist" in their constitutions.
A socialist state is to be distinguished from a multi-party liberal democratic state governed by a self-described socialist party, where the state is not constitutionally bound to the construction of socialism. In such cases, the political system and machinery of government is not specifically structured to pursue the development of socialism.