The term USSR Component can be summarized as the SOVIET Union, which was a Marxist-Leninist state that existed from 1922 to 1991. It was a single-party state governed by the Communist Party of the SOVIET Union, with Moscow as its capital. The SOVIET Union was a union of 15 SOVIET republics, and its official name was the Union of SOVIET Socialist Republics (USSR). The SOVIET Union was the largest country in the world by area, spanning over 8.7 million square miles. It was also one of the world's two superpowers, along with the United States.