The Potsdam conference was held in Potsdam, Germany (near Berlin), from July 17 to August 2, 1945. The participants were the victorious allies of World War II who were to decide how to administer Germany, which had unconditionally surrendered nine weeks earlier, on May 8.

Participants were:

The primary results of this conference were:

The western allies, and especially Churchill, were suspicious of the motives of Stalin, who had already installed communist governments in the eastern European countries under his influence; the Potsdam conference turned out to be the last conference among the allies.

During the conference, Truman told Stalin about his "powerful new weapon"; Stalin of course knew already about the atomic bomb through his spies in the Manhattan project. Toward the end of the conference, Japan was given an ultimatum (threatening "prompt and utter destruction" without mentioning the new bomb), and after Japan had rejected it, atomic bombs were dropped on Hiroshima and Nagasaki.