The rise of Truman was almost the same time as the fall of Churchill.
The UK general election had taken place on July 5, but the counting was delayed, waiting for the ballots from the overseas British troops.
Churchill made the unusual diplomatic decision to invite Attlee—who was the leader of the opposition Labour Party, to attend the conference together.
This setup was intentionally arranged so that IF the Labour Party won, Attlee would already be entirely up to speed on the secret negotiations.
It also showed the United States and the Soviet Union that British foreign policy would remain steady, regardless of domestic political shifts.
July 25, 1945: Churchill departed Germany. The conference paused its major sessions so the British delegation could fly back to the UK for the ballot counting.
July 26: The election results were officially announced. The Conservatives lost, Churchill immediately resigned, and Clement Attlee was sworn in as the new Prime Minister.
July 28: Prime Minister Clement Attlee returned to Cecilienhof Palace to take Churchill's seat at the negotiation table alongside Truman and Stalin for the remainder of the summit.
Churchill never returned to the palace, and his sudden political departure remains one of the most dramatic twists of modern diplomatic history.
Stalin was shocked and baffled. He could not comprehend how a victorious wartime leader could be dismissed by his own people.
As someone who had unexpectedly thrust into the presidency just weeks earlier, Truman understood the volatile nature of democratic transitions.