The establishment of the Soviet sphere post-World War II was largely driven by the Yalta Conference decisions, where Allied leaders agreed on postwar reorganization. The Soviet Union sought to expand its influence in Eastern Europe by installing communist governments to create a buffer zone against potential Western aggression. This led to the formation of various satellite states, which aligned with Soviet interests, as the USSR aimed to spread its ideology and counterbalance Western power. The resulting geopolitical tensions contributed to the onset of the Cold War, shaping global politics for decades.