For the purposes of this paper, we ask you to imagine that soon after Harry Truman became president in April 1945, he appointed you to look into issues surrounding the possible future use of atomic bombs and advise him concerning his options. You should assume that all of the relevant events occurred just as they actually did up to late July 1945, including the successful testing of the Trinity device in New Mexico on 16 July 1945 and the convening of the Potsdam Conference in Germany the next day. We ask that you write a 5–7 page paper (about 1500–2000 words), framed as a report to be delivered to President Truman on 24 July 1945, in which you analyze and evaluate the alternative courses of action available to him and advise him how best to proceed, particularly with respect to the possible use of atomic bombs. Note that your advice might involve altering the contents of the Potsdam Proclamation (issued on 26 July); issuing other statements concerning possible terms of Japanese surrender; issuing a warning or staging a demonstration of an atomic bomb; choosing different targets for such a bomb; or any other steps you might deem advisable. Your advice should take into account the ethical, diplomatic, political, and military dimensions of the possible use of atomic bombs, with regard both to the immediate task of bringing the war with Japan to a successful end and the longer term goal of achieving what Robert Oppenheimer called “a satisfactory adjustment of our international relations.” You should also address the larger issue of ethical action during wartime.
https://nsarchive.gwu.edu/briefing-book/nuclear-vault/2020-08-04/atomic-bomb-end-world-war-ii.