Excerpted from Henry Wallace, Harry Truman, and the Cold War by Richard J. Walton ©1976, Henry Wallace writes in his diary about meeting J. Robert Oppenheimer:
I never saw a man in such an extremely nervous state as Oppenheimer. He seemed to feel that the destruction of the entire human race was imminent… He has been in charge of the scientists in New Mexico and says that the heart has completely gone out of them there; that all they think about now are the social and economic implications of the bomb, and that they are no longer doing anything worthwhile on the scientific level… He says that… Secretary (James F.) Byrnes has felt that we could use the bomb as a pistol to get what we wanted in international diplomacy. Oppenheimer believes that method will not work. He says the Russians are a proud people and have good physicists and abundant resources. They may have to lower their standard of living to do it but they will put everything they have got into getting plenty of atomic bombs as soon as possible. He thinks the mishandling of the situation at Potsdam has prepared the way for the eventual slaughter of tens of millions or perhaps hundreds of millions of innocent people.
The guilt consciousness of the atomic bomb scientists is one of the most astounding things I have ever seen.
That’s the part of warfare that isn’t mentioned very much. After all the flags have been waved, the medals have been pinned to chests, and the post-parade confetti swept up and put into bins, the participants are left alone to reconcile their consciences with the terrible things they have done.