I have heard very few veterans of the Pacific war who opposed the use of nuclear weapons.
In one of my favorite books, “Surely You’re Joking, Mr. Feynman”, Richard Feynman talked about the supposed hand-wringing in the scientific community about the bomb, and said there was very little of it. Everyone thought it should be used, and was of the opinion that all the hand-wringing and soiled consciences came after the fact...
Indeed.
Later an advisory committee of four physicists actively involved in development joined them. They were Enrico Fermi and Arthur H. Compton of the University of Chicago; Ernest O. Lawrence of the Radiation Laboratory at University California Berkley; and J. Robert Oppenheimer head of the Los Alamos Laboratory where the bombs were being assembled.
The committee and scientific panel reached three unanimous conclusions, which Truman reluctantly agreed to, because he could see no alternative.
The bomb should be used against Japan as soon as possible.
It should be used against war plants surrounded by worker’s homes and other buildings susceptible to damage, in order to make as profound a psychological impression on as many inhabitants as possible.
It should be used without warning.
I think my source is Hell to Pay by D. M. Giangreco.