1) Joseph Stalin consolidated power in the Soviet Union and led the country as General Secretary of the Communist Party from the 1920s-1950s. 2) Under Stalin, the Soviet Union rapidly industrialized and collectivized agriculture through five-year plans and brutal policies, establishing the USSR as a major world power but at tremendous human cost. 3) Stalin's totalitarian rule relied on fear, propaganda, and state terror through the secret police to maintain control and push for rapid modernization, imprisoning and executing millions who opposed him.