Stalin was focused on growing influence and ideological expansion. He was confident in establishing his sphere of influence after Yalta, and he managed to create a buffer zone by 1948, instilling Communist regimes across Eastern Europe (Poland, Hungary, Bulgaria, Romania, Albania, and Czechoslovakia). This buffer zone would reinforce the USSR’s defensive capability against threats from the West, but while security was a clear aim for Stalin, it was also apparent that he wanted to use this to spread Communism.
Communist expansion also came in the form of alliances with other left-wing parties (often taking control of them) and manipulating election results.
However, in some areas, such as post-war Czechoslovakia, Communism was welcomed as it offered a much better prospect than Capitalism - promising employment and social mobility.