Stalinism

The Stalinist version of socialism, with some important modifications, shaped the Soviet Union and influenced Communist Parties worldwide. It was heralded as a possibility of building communism via a massive program of industrialization and collectivization. The rapid development of industry, and above all the victory of the Soviet Union in the Second World War, maintained that vision throughout the world, even around a decade following Stalin's death, when the party adopted a program in which it promised the establishment of communism within thirty years.
However, under Stalin's leadership, evidence emerged that dented faith in the possibility of achieving communism within the framework of the Soviet model. Stalin had created in the Soviet Union a repressive state that dominated every aspect of life. Later, growth declined, and rent-seeking and corruption by state officials increased, which dented the legitimacy of the Soviet system.
Despite the activity of the Comintern, the Soviet Communist Party adopted the Stalinist theory of "socialism in one country" and claimed that, due to the "aggravation of class struggle under socialism," it was possible, even necessary, to build socialism in one country alone.This departure from Marxist internationalism was challenged by Leon Trotsky, whose theory of "permanent revolution" stressed the necessity of world revolution.