Having seized power in 1917, the Bolsheviks didn’t plan on stopping there. Their plans were far more ambitious than setting up a socialist system just at home: communism was to become victorious the world over.
According to Marxist ideology, a revolution that began in one country would inevitably spread to others, in the end ensuring the global supremacy of the working proletariat. “The socialist revolution in Europe must come and it will,” Vladimir Lenin wrote in January 1918: “All our hopes for the final victory of socialism are based on a certainty in this forecast.”
The Bolsheviks actively supported revolutionary movements abroad, aiding their proletarian comrades abroad in any way possible, including through the Komintern - an international organization that unified all of the countries’ communist parties under one banner.
The Soviet-Polish war of 1919-1921 became the perfect chance for Moscow to sovietize Europe along with Russia. “Through the dead body of ‘white’ Poland lies the path toward a global fire. The happiness of the world’s working humanity shall be carried on bayonets! To the West!” - such was the impassioned proclamation delivered by Mikhail Tukhachevsky, commander of the Western front.
However, an unexpected and severe defeat incurred by the Red Army under Warsaw in August 1920 put an end both to the victory in the war and any plans to export the Revolution to Europe by way of the bayonet. Moreover, the red revolutionary forces of the world were experiencing failure elsewhere, while German, Hungarian, Romanian, Slovak and Iranian “Soviet” republics proved to be fragile and short-lived. In addition to that, Moscow had soon realized that it could not make do without diplomatic and trade relations with Western powers.
From the mid-1920s, the ideas of a Global Revolution, of military aggression toward capitalist countries and open support of revolutionary movements there began to fade from the minds of Soviet command. The USSR began a more covert and delicate campaign to achieve the spread of communism.