Final Answer:
The breakdown in relations between the Soviet Union and its wartime allies was primarily fueled by conflicting ideologies and geopolitical interests discussed during the Yalta and Potsdam Conferences.
Step-by-step explanation:
The Yalta Conference, held in February 1945, marked the first major post-war meeting between the Allied leaders: Franklin D. Roosevelt, Winston Churchill, and Joseph Stalin. The discussions during Yalta revealed the fundamental ideological differences between the Soviet Union and its Western allies. While the Allies agreed on defeating Nazi Germany, the Soviet Union sought to establish a sphere of influence in Eastern Europe, alarming the West. The seeds of discord were planted as Stalin's ambitions clashed with the principles of self-determination and democracy advocated by the United States and the United Kingdom.
The Potsdam Conference in July 1945 exacerbated the tensions. By this time, Truman had succeeded the late Roosevelt, and Churchill was replaced by Clement Attlee. The shifting political landscape further strained relations. Disagreements arose over the post-war order in Europe, particularly the division of Germany and the fate of Eastern European countries. The West became increasingly wary of Soviet expansionism, setting the stage for the emerging Cold War. The atomic bomb's successful testing by the U.S. further shifted the balance of power and influenced Truman's approach, contributing to the breakdown in relations as both sides entrenched themselves in opposing ideological camps.
In conclusion, the Yalta and Potsdam Conferences highlighted the irreconcilable differences in the post-war visions of the Soviet Union and its Western allies. The geopolitical and ideological clashes during these conferences set the groundwork for the deteriorating relations that ultimately led to the Cold War.