Through these channels, Stalin became aware of the beginnings of a bomb program in Britain by 1940, with knowledge of the upcoming American program soon to follow
Germany in 1941–45, and extended Soviet controls to include a belt of eastern European states. Chief architect of Soviet totalitarianism and a skilled but phenomenally ruthless organizer, he destroyed the remnants of individual freedom and failed to promote individual prosperity, yet he created a mighty military-industrial complex and led the Soviet Union.
During the quarter of a century preceding his death, the Soviet dictator Joseph Stalin probably exercised greater political power than any other figure in history. Stalin industrialized the Union of Soviet Socialist Republics, forcibly collectivized its agriculture, consolidated his position by intensive police terror, helped to defeat Germany in 1941–45, and extended Soviet controls to include a belt of eastern European states.