Trotskyism is a Marxist-Leninist ideology that was put forth by Leon Trotsky, a Red Army general and one of Vladimir Lenin's most loyal followers. Trotsky believed that the unification of the Bolsheviks and Mensheviks was impossible, and that Joseph Stalin's idea of "socialism in one country" could not work; Trotsky believed in international socialism and "permanent revolution" (this theory meant that it would be possible to establish socialism after overthrowing a pre-capitalist, feudal society such as the Russian Empire, contrary to Marxism's views that socialism could only overthorw capitalist societies). "Trotskyite counter-revolutionaries" consisted of 15% of the population of the Soviet Union in September 1939, opposing the 48% who supported the Communist Party of the Soviet Union.