One of the most controversial topics of the Potsdam conference was the revision of the German-Soviet-Polish borders and the expulsion of millions of Germans from the disputed territories. In exchange for the territory it lost after the rebalancing of the Soviet-Polish border to the Soviet Union, Poland received much of German territory and began deporting German residents from the territories concerned, as well as other nations that held large German minorities. The Negotiators in Potsdam were well aware of the situation and, although the British and Americans feared that a mass exodus of Germans to Western areas of occupation would destabilize them, they merely stated that “all transfers that take place should be done in an orderly and humane manner" and asked the Poles, Czechs and Hungary to temporarily suspend the additional deportations. The Soviet Union presented to the Conference a proposal on the territories related to the mandate, in accordance with what was decided at the Yalta Conference and the Charter of the United Nations. Shortly before the conference began on July 16, 1945, the United States successfully detonated a nuclear bomb at its test site in the New Mexico desert. When Truman first reported on the success of the experiment, he would have noticed that if it worked… I`m probably going to have a hammer on these guys. In Potsdam, Truman decided to tell Stalin that the United States possessed a new weapon of unusual destructive force. Although Stalin already knew details about the Manhattan project through his spy networks, he could complain about this treatment and the fact that there were secrets between alleged allies. Given that Italy`s provision was one of the most important issues that required the attention of the new Council of Foreign Ministers; the three governments were particularly concerned about the conclusion of a peace agreement with it, especially since Italy was the first of the Axis powers to disserfy with Germany and to participate in allied operations against Japan. To remember the things that were discussed at each conference, use the mnemonic PEER The main objective of the Potsdam conference was to put an end to the post-war rule and put into practice everything that had been agreed to in Yalta.
While the Yalta meeting was rather friendly, the Potsdam conference was marked by differences of opinion that were the result of some important changes since the Yalta conference. In Potsdam, little real progress has been made, beyond an agreement on fulfilling the commitments made in Yalta. Truman was much more suspicious of the Soviets than Roosevelt and increasingly suspicious of Stalin`s intentions.  Truman and his advisers regarded Soviet action in Eastern Europe as aggressive expansionism, incompatible with the agreements Stalin had been obliged to in Yalta in February.