structural:reformatting
Eastern Bloc

After the war, Stalin sought to retain Soviet dominance across Eastern Europe while expanding its influence in Asia. Cautiously regarding the responses from the Western Allies, Stalin avoided immediately installing Communist Party governments across Eastern Europe, instead initially ensuring that Marxist-Leninists were placed in coalition ministries. In contrast to his approach to the Baltic states, he rejected the proposal of merging the new communist states into the Soviet Union, rather recognising them as independent nation-states. He was faced with the problem that there were few Marxists left in Eastern Europe, with most having been killed by the Nazis. He demanded that war reparations be paid by Germany and its Axis allies Hungary, Romania, and the Slovak Republic. Aware that these countries had been pushed toward socialism through invasion rather than by proletarian revolution, Stalin referred to them not as "dictatorships of the proletariat" but as "people's democracies", suggesting that in these countries there was a pro-socialist alliance combining the proletariat, peasantry, and lower middle-class.

Churchill observed that an " Iron Curtain " had been drawn across Europe, separating the east from the west. In September 1947, a meeting of East European communist leaders was held in Szklarska Poręba, Poland, from which was formed Cominform to co-ordinate the Communist Parties across Eastern Europe and also in France and Italy. Stalin did not personally attend the meeting, sending Zhdanov in his place. Various East European communists also visited Stalin in Moscow. There, he offered advice on their ideas; for instance, he cautioned against the Yugoslav idea for a Balkan Federation incorporating Bulgaria and Albania. Stalin had a particularly strained relationship with Yugoslav leader Josip Broz Tito due to the latter's continued calls for a Balkan federation and for Soviet aid for the communist forces in the ongoing Greek Civil War. In March 1948, Stalin launched an anti-Tito campaign, accusing the Yugoslav communists of adventurism and deviating from Marxist–Leninist doctrine. At the second Cominform conference, held in Bucharest in June 1948, East European communist leaders all denounced Tito's government, accusing them of being fascists and agents of Western capitalism. Stalin ordered several assassination attempts on Tito's life and even contemplated an invasion of Yugoslavia itself.

Stalin suggested that a unified, but demilitarised, German state be established, hoping that it would either come under Soviet influence or remain neutral. When the U.S. and UK remained opposed to this, Stalin sought to force their hand by blockading Berlin in June 1948. He gambled that the Western powers would not risk war, but they airlifted supplies into West Berlin until May 1949, when Stalin relented and ended the blockade. In September 1949 the Western powers transformed Western Germany into an independent Federal Republic of Germany; in response the Soviets formed East Germany into the German Democratic Republic in October. In accordance with their earlier agreements, the Western powers expected Poland to become an independent state with free democratic elections. In Poland, the Soviets merged various socialist parties into the Polish United Workers' Party (PZPR), and vote rigging was used to ensure that the PZPR secured office. The 1947 Hungarian elections were also rigged by Stalin, with the Hungarian Working People's Party taking control. In Czechoslovakia, where the communists did have a level of popular support, they were elected the largest party in 1946. Monarchy was abolished in Bulgaria and Romania. Across Eastern Europe, the Soviet model was enforced, with a termination of political pluralism, agricultural collectivisation, and investment in heavy industry. It was aimed at establishing economic autarky within the Eastern Bloc.