All changed, when 22nd of June 1941, Hitler having conquered most of the Western Europe, invaded the USSR.
The Great Patriotic war for USSR began; after heavy fights the Soviet Army's successful campaigns on the Eastern Front culminated in capture of Berlin. Soviet deaths, most of them civilian victims, and soldiers in ghastly land battles.
Tsar Nicholas II and his wife, a granddaughter of Queen Victoria, proved to be feckless, weak, and distracted by personal tragedies and the burdens of the war.
In addition to forced collectivization of agriculture and renationalisation of industries, Stalin introduced a ruthlessly centralized economic system ("socialism in one country") that rapidly industrialized the USSR.The revolutionary state was not directly ruled by the officials in titular control of the government, which was established in the name of the Union of Soviet Socialist Republics (USSR).The government in the commonly understood sense was largely irrelevant both in fact and in Communist theory throughout the years of Communist control.After Stalin's death in 1953, Soviet heavy industry and military might continued to grow under Georgy Malenkov (1953-1955) and Nikita Khrushchev (1955-1964), as General Secretary of the Communist Party.Attempts were made to produce consumer goods, as well as a progressive decentralization, despite resistance from the armed forces.
In a manner akin to the Tsarist regime, the real power lay in the leadership of the Communist Party, the Red Army, and the internal security apparatus (secret police).