The Potsdam Conference (German: Potsdamer Konferenz) was held at Potsdam in the Soviet occupation zone from 17 July to 2 August 1945, to allow the three leading Allies to plan the postwar peace, while avoiding the mistakes of the Paris Peace Conference of 1919. The participants were the Soviet Union, the United Kingdom, and the United States. They were represented respectively by General Secretary Joseph Stalin, prime ministers Winston Churchill and Clement Attlee, and President Harry S. Truman. They gathered to decide how to administer Germany, which had agreed to an unconditional surrender nine weeks earlier. The goals of the conference also included establishing the postwar order, solving issues on the peace treaty, and countering the effects of the war.
The foreign ministers and aides played key roles: Vyacheslav Molotov, Anthony Eden and Ernest Bevin, and James F. Byrnes. From 17 July to 25 July, nine meetings were held, when the Conference was interrupted for two days, as the results of the British general election were announced. By 28 July, Attlee had defeated Churchill and replaced him as Britain's representative, with Britain's new Secretary of State for Foreign Affairs, Ernest Bevin, replacing Anthony Eden. Four days of further discussion followed. During the conference, there were meetings of the three heads of government with their foreign secretaries, as well as meetings of only the foreign secretaries. Committees that were appointed by the latter for precursory consideration of questions before the conference also met daily. During the Conference, Truman was secretly informed that the Trinity test of the first atomic bomb on 16 July had been successful. He hinted to Stalin that the U.S. was about to use a new kind of weapon against the Japanese. Though this was the first time the Soviets had been officially given information about the atomic bomb, Stalin was already aware of the bomb project, having learned about it through espionage long before.
Key final decisions included the following: Germany would be divided into the four occupation zones (among the three powers and France) that had been agreed to earlier; Germany's eastern border was to be shifted west to the Oder–Neisse line; a Soviet-backed group was recognized as the legitimate government of Poland; and Vietnam was to be partitioned at the 16th parallel. The Soviets also reaffirmed their Yalta promise to promptly launch an invasion of Japanese-held areas.
Views were also exchanged on a plethora of other questions. However, consideration of those matters was postponed into the Council of Foreign Ministers, which the conference established. The conference ended with a stronger relationship among the three governments as a consequence of their collaboration, which renewed confidence that together with the other United Nations, they would ensure the creation of a just and enduring peace. Nevertheless, within 18 months relations had deteriorated and the Cold War had emerged.
In May 1945, Churchill wrote to Truman hoping to arrange a meeting of the three governments to occur in June. Truman hoped for Stalin to propose the meeting so as to avoid the appearance that the Americans and British were ganging up on the Soviets. With some prompting from Truman's aide Harry Hopkins, Stalin proposed a meeting in the Berlin area. Informed of this by the US, Churchill sent a letter agreeing that he'd be happy to meet in "what is left of Berlin".
Some sources suggest Truman delayed the conference in order for it to meet after the results of the first atomic bomb test were known. The conference was eventually set to begin on 16 July at Cecilienhof in Potsdam, near Berlin.
A number of changes had taken place in the five months since the Yalta Conference and greatly affected the relationships among the leaders. The Soviets occupied Central and Eastern Europe. The Baltic states were forcibly reincorporated into the USSR, while the Red Army also occupied Poland, Czechoslovakia, Hungary, Bulgaria, and Romania. Refugees fled from those countries. Stalin had set up a puppet communist government in Poland, insisted that his control of Eastern Europe was a defensive measure against possible future attacks, and claimed that it was a legitimate sphere of Soviet influence.
Winston Churchill, who had served for most of the war as British prime minister in a coalition government, was replaced during the conference by Clement Attlee. Churchill's government had a Soviet policy since the early 1940s that differed considerably from Franklin D. Roosevelt's and believed Stalin to be a "devil"-like tyrant, who led a vile system. A general election had been held in the United Kingdom on 5 July 1945, but its results were delayed to allow the votes of armed forces personnel serving overseas to be counted in their home constituencies. The outcome became known on 26 July during the conference, when Attlee became the new prime minister.
Roosevelt had died on 12 April 1945, and US Vice–President Harry Truman assumed the presidency, which saw VE Day (Victory in Europe) within a month and VJ Day (Victory in Japan) on the horizon.
William Bullitt had been ambassador to the Soviet Union until 1936, and ambassador to France until 1940, until having a falling out with Roosevelt and a demotion in the State Department. He later claimed Roosevelt told him in January 1943 with regards to potential Soviet domination over eastern Europe—"I just have a hunch that Stalin is not that kind of a man. ... I think that if I give him everything I possibly can and ask for nothing from him in return, 'noblesse oblige', he won't try to annex anything and will work with me for a world of democracy and peace." Bullitt wrote a memo criticizing FDR and his focus on Europe over Asia, which was published in the press in May 1943.
While a United States Senator and later as Vice President, Truman had closely followed the Allied progress of the war. George Lenczowski noted that "despite the contrast between his relatively modest background and the international glamour of his aristocratic predecessor, [Truman] had the courage and resolution to reverse the policy that appeared to him naive and dangerous," which was "in contrast to the immediate, often ad hoc moves and solutions dictated by the demands of the war." With the end of the war, the priority of Allied unity was replaced by the challenge of the relationship between the two emerging superpowers. Both leading powers continued to portray a cordial relationship to the public, but suspicion and distrust lingered between them. Despite this, on 17 July, the first day of the conference, Truman noted "I can deal with Stalin. He is honest—but smart as hell."
Truman was much more suspicious of the Soviets than Roosevelt had been and became increasingly suspicious of Stalin's intentions. Truman and his advisers saw Soviet actions in Eastern Europe as aggressive expansionism, which was incompatible with the agreements committed to by Stalin at Yalta in February. In addition, Truman became aware of possible complications elsewhere after Stalin had objected to Churchill's proposal for an Allied withdrawal from Iran ahead of the schedule that had been agreed at the Tehran Conference. The Potsdam Conference was the only time that Truman met Stalin in person.
At the Yalta Conference, France was granted an occupation zone within Germany. France was a participant in the Berlin Declaration and was to be an equal member of the Allied Control Council. Nevertheless, at the insistence of the Americans, Charles de Gaulle was not invited to Potsdam—just as he had been denied representation at Yalta—for fear that he would reopen the Yalta decisions. De Gaulle thus felt a diplomatic slight, which became a cause of deep and lasting resentment for him. Other reasons for the omission included the longstanding personal mutual antagonism between Roosevelt and de Gaulle, ongoing disputes over the French and American occupation zones, and the anticipated conflicts of interest over French Indochina. It also reflected the judgement of the British and the Americans that French aims, with respect to many items on the conference's agenda, were likely to contradict agreed-upon Anglo-American objectives.