What factors contributed to the acquisition of the USSR the status of a leading world power?

Withdrawal from WWII as a winner significantly increased the world prestige of the state. The successes in the development of the industry before the war and the rapid recovery after it created the economic prerequisites for further growth. Advances in the development of nuclear physics have made it possible to create weapons of mass destruction; this made Western countries always wary of the possibility of a real armed conflict. Development in the direction of building a welfare state also proceeded successfully, so the Soviet model became a reference point for a number of developing countries, and capitalist countries had to take this into account when conducting their own domestic policies.