Final answer:
At the Potsdam Conference, the Allied leaders, including Truman, Attlee, and Stalin, agreed to divide Germany and Berlin into sectors but disagreed on the size of reparations from Germany. Distrust between the US and Soviet Union colored the negotiations, exacerbated by the US testing of an atomic bomb.
Step-by-step explanation:
The Potsdam Conference, held in July - August 1945, was a significant meeting between the leaders of the Allied powers to discuss the reconstruction of Europe following World War II. The leaders in attendance at this critical conference included the new U.S. President Harry Truman, British Prime Minister Clement Attlee, and Soviet Premier Joseph Stalin. They made several decisions, notably the division of Germany and Berlin into four sectors controlled by the American, British, French, and Soviet forces. However, disagreements arose related to how much reparations Germany should pay, with Stalin demanding substantial reparations and Truman concerned about the burden on Germany and the potential for future conflict.
Additional tensions were also present due to the general distrust between the Soviet Union and the United States. Truman had received word about the successful testing of the atomic bomb during the conference, which could only have intensified the distrust. While the use of atomic bombs on Japan was not a primary point of disagreement at Potsdam itself, it certainly added to the complexity of the postwar relationships.