Soyuz Sovjetskih Socialistickih Republik, SSSR was a union of Soviet republics. the USSR grew to contain 15 union republics: Armenian SSR, Azerbaijan SSR, Byelorussian SSR, Estonian SSR, Georgian SSR, Kazakh SSR, Kyrgyz SSR, Latvian SSR, Lithuanian SSR, Moldavian SSR, Russian SFSR, Tajik SSR, Turkmen SSR, Ukrainian SSR, and Uzbek SSR. The Soviet Union became the primary model for future Communist states during the Cold War; the government and the political organization of the country were defined by the only political party, the Communist Party of the Soviet Union.