If you mean the cities, he did not pick them he left them up to his generals from a preselected list of about half a dozen. Nagasaki was a secondary target picked by the flight crew as the primary was clouded over.
He told the president about Hitler's atomic bomb.
Albert Einstein wrote a letter to the president in 1939 warning him about the possibility of an atomic bomb.
Einstein made recommendations to FDR to develop atomic weapons before the Nazis did .
Because they needed a weapon to defeat the Japanese, and many prestigious scientists, including Einstein himself, mailed the president to tell him of the potential power of an atomic bomb.
His theory about atomic fusion helped in the development of the bomb. He also convinced the president to develop the research in it. In the last 25 years of his life he questioned himself concerning the use and development of the bomb and was unhappy that he had helped build the theory and foundation of atomic theory.
President Harry Truman.
The US President Harry Truman.
President Truman got the order to use them against Japan.
I believe it was the president, Harry S. Truman
truman
While the development of the atomic bomb was initiated under FDR, Harry S Truman was president when the final decision was made to drop the bomb.
princess patrick harwood President Truman
President Truman
President Truman
President Truman.
Harry Truman
President Harry Truman gave the order for atomic bombs to be dropped on Hiroshima and Nagasaki.