Depends on which one. There was USSR before, during and after Stalin. Stalin took over agrarian country devastated by the civil war, famine and filled with uneducated people. In 10 years he managed to build thousands of factories to outproduce the entire Europe that fought against the USSR in WWII. During the war the GDP of the USSR was 14%. By the time Stalin died, the USSR had the most educated population on the planet. They built the first nuclear power plant, were getting ready to launch Sputnik, and the stores were full of goods. Stalin said that Communists developed the science of a revolution but failed to come up with a plan to run the country. Stalin ended the Worldwide Communism project of the Neoliberals, closed the USSR’s central bank in New York, and removed the Communist Party from power. For that last step the Neoliberals killed him, falsified history and eventually destroyed the USSR.