The nuclear road not taken

August 6, 2025 Arjun Makhijani

It all started in 1939, when Albert Einstein signed a letter, drafted by Leo Szilard, to US President Franklin D. Roosevelt, warning that Nazi Germany might develop “extremely powerful bombs of a new type” and urging him to act to prevent Hitler from getting an atomic bomb monopoly. The fear was legitimate. Only one scientist, Joseph Rotblat, quit the Manhattan Project in December 1944, when it became clear that Hitler did not have a viable atomic bomb program. None quit when Germany was defeated; looking back at that moment, another Los Alamos scientist, Richard Feynman, said in a 1981 BBC interview that he “immorally” failed to “reconsider” his continued participation after Germany was defeated. “I simply didn’t think, okay?” he declared.

Members of the US Army examine the area around ground zero in Hiroshima, Japan, autumn 1945. Prisma Bildagentur / Getty Images