Leo Szilard played an enormously important role in the development of the first atomic bombs. His eccentricities are oft mentioned. His core strengths as a physicist were not the complex maths of a theory, nor in conducting imaginative experiments. Rather he was a big-picture thinker, a prodigious one. After WWII ended, he retained some atomic charisma but quickly moved on to biology. One of his last atomic forays was a speech he gave in Spokane (I’m not sure to whom) in April of 1947. He begins by saying, “During the war we gave very little attention to the peace-time applications of atomic energy.” He explains fission, about the possibility of breeding, about how to get electricity from the atom, including (long-term) from plutonium obtained from breeders.
He closes thus:
“Unfortunately, economic considerations are overshadowed by political considerations. Unfortunately plutonium is not only an important atomic fuel, it is also the chief ingredient of atomic bombs. Can we afford to have atomic power unless we are safe from bombs? And can we be safe from bombs unless we can count on peace?”Szilard, Leo. 1947. Atomic Energy, a Source of Power or a Source of Trouble: Speech at Spokane, Washington, Apr. 23, 1947. http://library.ucsd.edu/dc/object/bb43701801/_1.pdf (accessed Apr. 28, 2020).
We’re still asking those questions in 2021. Nuclear disarmament and nuclear nonproliferation remain vital.