Potsdam Conference
The last wartime summit, held in a defeated Germany in July 1945, where the alliance divided Europe and the Cold War became visible.
Potsdam was the third and last meeting of the Big Three, held at the Cecilienhof palace outside a flattened Berlin from 17 July to 2 August 1945. Yalta five months earlier had been a conference of allies planning a victory. Potsdam was a conference of rivals dividing a corpse. Almost everything that structured Europe for the next forty-five years was fixed, or failed to be fixed, in those two weeks.
Three men, and the ground shifting under them
The cast had changed and that changed everything. Roosevelt was dead, replaced by Harry Truman, who had been vice president for twelve weeks, had not been briefed on the atomic program until he took office, and had none of Roosevelt's belief that he could personally manage Stalin. Churchill arrived, then vanished halfway through: Britain's general election results came in on 26 July, Labour had won, and Clement Attlee returned to the table as prime minister on the 28th. Only Stalin was there from start to finish, and only Stalin had an army sitting on every territory under discussion.
On 24 July, Truman told Stalin, deliberately casually, that the United States had a new weapon of unusual destructive force. Stalin, who knew about the Manhattan Project through Soviet intelligence and had known for longer than Truman had, replied that he hoped it would be put to good use against Japan. The Trinity test had succeeded eight days earlier. The bomb sat under the whole conference and was never openly discussed.
What was decided
Germany was to be governed as a single economic unit by four occupation zones under an Allied Control Council, and subjected to what became known as the five Ds: demilitarization, denazification, democratization, decentralization, and dismantling of industry. Reparations would be taken by each power primarily from its own zone, a formula that sounded like a compromise and functioned as a partition, because it meant the Soviets could strip their zone as they liked and nobody could stop them.
Germany's eastern border was moved west to the Oder and Neisse rivers, handing large territories to Poland, whose own eastern lands the Soviet Union had taken. The conference approved the transfer of German populations out of Poland, Czechoslovakia, and Hungary in what it called an orderly and humane manner. The expulsion of some twelve million Germans that followed was neither.
On 26 July the United States, Britain, and China issued the Potsdam Declaration demanding Japan's unconditional surrender or face prompt and utter destruction. The Soviet Union, still neutral in the Pacific, did not sign. Japan's government responded with a statement that was read in Washington as rejection. Hiroshima was bombed four days after the conference ended.
Where it broke
What Potsdam could not settle was Eastern Europe. At Yalta, Stalin had promised free elections in the liberated countries. By July, Soviet-backed governments were being installed in Poland, Romania, and Bulgaria, and the Western leaders discovered they had no leverage that did not involve threatening war with an army of eleven million men sitting exactly where the dispute was.
That is the conference's real significance. Yalta is popularly blamed for handing Eastern Europe to Stalin, but Yalta produced words. Potsdam is where the Western allies found out the words meant nothing and decided, without ever saying so, to accept it. Truman left believing Stalin could not be dealt with. Kennan's Long Telegram came seven months later, Churchill's iron curtain speech a month after that, and the Truman Doctrine a year after that.
The zones drawn at Potsdam became West and East Germany. The Oder-Neisse line is Poland's border today, confirmed by treaty only after reunification in 1990, because the final German peace settlement that Potsdam deferred did not arrive for forty-five years.