Socialism in One Country (Russian: Социализм в одной стране Sotsializm v odnoi strane) was a theory put forth by Nikolai Bukharin and implemented by Joseph Stalin in 1924, and finally adopted by the Soviet Union as state policy. The theory held that given the defeat of all the communist revolutions in Europe in 1917–1923 except Russia's, the Soviet Union should begin to strengthen itself internally. That turn toward national communism was a shift from the previously held position by Classical Marxism that socialism must be established globally (world communism). However, the proponents of the theory contend that it contradicts neither world revolution nor world communism. The theory was in opposition to Leon Trotsky's theory of permanent revolution.