USSR meaning in Governmental ?

The Ukrainian Soviet Socialist Republic (Ukrainian SSR, UkrSSR or UkSSR; Ukrainian: Украї́нська Радя́нська Соціалісти́чна Респу́бліка, romanized: Ukrayins'ka Radians'ka Sotsialistychna Respublika, УРСР; Russian: Украи́нская Сове́тская Социалисти́ческая Респу́блика, УССР), also known as Soviet Ukraine, was one of the constituent republics of the Soviet Union from the Union's inception in 1922 until its breakup in 1991. In the anthem of the Ukrainian Soviet Socialist Republic, the republic was referred to simply as Ukraine. The republic was governed by the Communist Party of the Soviet Union through its republican branch, the Communist Party of Ukraine, as a union republic of the Soviet Union, which existed as a highly centralized one-party state.

The Ukrainian SSR was established by the Bolsheviks following the defeat of the Ukrainian People's Republic in the Soviet–Ukrainian War during the Russian Civil War. As a Soviet proto-state, the Ukrainian SSR became a founding member of the United Nations along with the Byelorussian SSR, even though they were legally represented by the All-Union state in its affairs with countries outside of the Soviet Union. Upon the Soviet Union's dissolution and perestroika, the Ukrainian SSR was transformed into the independent state of Ukraine.

Throughout its 72-year history, the republic's borders changed many times, with a significant portion of what is now Western Ukraine being annexed by Soviet forces in 1939 from the Republic of Poland, and the addition of Carpathian Ruthenia from Czechoslovakia in 1945. From its establishment, the eastern city of Kharkov served as the republic's capital. However, the seat of government was subsequently moved in 1934 to the city of Kiev, Ukraine's historic capital. Kiev remained the capital for the rest of the Ukrainian SSR's existence and remained the capital of independent Ukraine after the breakup of the Soviet Union.

Geographically, the Ukrainian SSR was situated in Eastern Europe to the north of the Black Sea, bordered by the Soviet republics of Moldavia, Byelorussia, and Russia. The Ukrainian SSR's border with Czechoslovakia formed the Soviet Union's westernmost border point. According to the 1989 Soviet Census, the republic had a population of 51,706,746 inhabitants, which fell sharply after the breakup of the Soviet Union.