Socialism in One Country ( Sotsializm v odnoi strane) was a theory put forth by Joseph Stalin in 1924, elaborated by Nikolai Bukharin in 1925 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 1917–1921 except Russia's, the Soviet Union should begin to strengthen itself internally. That turn toward national communism was a shift from the previously held Marxist position that socialism must be established globally (world communism), and it was in opposition to Leon Trotsky's theory of permanent revolution.