Impossible decisions remain impossible, even after they’ve been made. Following on yesterday’s post, here are the voices of those scientists and politicians who admitted the horror of the atomic bomb, but saw its creation and deployment as unavoidable; who felt caught up and even powerless in the equally inevitable march of scientific discovery; those who naively thought that such a horrible weapon would actually put an end to war altogether; and finally those for and against the development of the hydrogen bomb.
Robert Oppenheimer: It is a profound and necessary truth that the deep things in science are not found because they are useful; they are found because it was possible to find them.
Physicist Carl F. von Weizsacker, who worked in the German equivalent of the Manhattan project: To a person finding himself at the beginning of an era, its simple fundamental structures may become visible like a distant landscape in the flash of a single stroke of lightning. At that time  we were faced with a very simple logic. Wars waged with atomic bombs as regularly recurring events, that is to say, nuclear wars as institutions, do not seem reconcilable with the survival of the participating nations. But the atom bomb exists. It exists in the minds of some men. According to the historically known logic of armaments and power systems, it will soon make its physical appearance. If that is so, then the participating nations and ultimately mankind itself can only survive if war as an institution is abolished.
Physicist Leo Szilard, 1939: We realized that, should atomic weapons be developed, no two nations would be able to live in peace with each other unless their military forces were controlled by a common higher authority. We expected these controls, if they were effective enough to abolish atomic warfare, would be effective enough to abolish also all other forms of war. This hope was almost as strong a spur to our endeavors as was our fear of becoming the victims of the enemy’s atomic bombings.
British chemist and physicist Francis Aston, in a 1936 lecture: …there are those about us who say that such research should be stopped by law, alleging that man’s destructive powers are already large enough. So, no doubt, the more elderly and ape-like of our prehistoric ancestors objected to the use of the newly discovered agency, fire. Personally, I think there is no doubt that sub-atomic energy is all around us, and that one day man will release and control its almost infinite power. We cannot prevent him from doing so and can only hope that he will not use it exclusively in blowing up his next door neighbor.
From the MAUD (Military Application of Uranium Detonation) report, a British committee initiated before they backed the American Manhattan project: In spite of this very large expenditure we consider that the destructive effect, both material and moral, is so great that every effort should be made to produce bombs of this kind…. the material for the first bomb could be ready by the end of 1943. Even if the war should end before the bombs are ready the effort would not be wasted, except in the unlikely event of complete disarmament, since no nation would dare to risk being caught without a weapon of such destructive capabilities.
American Secretary of War Henry Stimson, who said that the bomb should be thought of “[not just] as a new weapon merely but as a revolutionary change in the relations of man to the universe”, and that it was “a Frankenstein which would eat us up” and “went far beyond the needs of the present war.”
Physicist Robert Wilson, on why he continued work on the atomic bomb after Germany had surrendered: It was to be the end of war as we knew it, and this was a promise that was made. That is why I could continue on that project.
President Harry Truman, looking back: We regarded the matter of dropping the [atomic] bomb as exceedingly important. We had just gone through a bitter experience at Okinawa [the last major island campaign, when the Americans lost more than 12,500 men killed and missing and the Japanese more than 100,000 killed in eighty-two days of fighting]. This had been preceded by a number of similar experiences in other Pacific islands, north of Australia. The Japanese had demonstrated in each case they would not surrender and they would fight to the death…. It was expected that resistance in Japan, with their home ties, would be even more severe. We had had the one hundred thousand people killed in Tokyo in one night of [conventional] bombs, and it had had seemingly not effect whatsoever. It destroyed the Japanese cities, yes, but their morale was not affected as far as we could tell, not at all. So it seemed quite necessary, if we could, to shock them into action…. We had to end the war; we had to save American lives.
Edward Teller, later father of the hydrogen bomb; he initially opposed using the atomic bomb, but came to this conclusion in July, 1945: First of all let me say that I have no hope of clearing my conscience. The things we are working on are so terrible that no amount of protesting or fiddling with politics will save our souls…. But I am not really convinced of your objections. I do not feel that there is any chance to outlaw any one weapon. If we have a slim chance of survival, it lies in the possibility to get rid of wars. The more decisive a weapon is the more surely it will be used in any real conflict and no agreements will help. Our only hope is in getting the facts of our results before the people. This might help to convince everybody that the next war would be fatal. For this purpose actual combat use might even be the best thing.
Physicist Leo Szilard: If peace is organized before it has penetrated the public’s mind that the potentialities of atomic bombs are a reality, it will be impossible to have a peace that is based on reality…. Making some allowances for the further development of the atomic bomb in the next few years … this weapon will be so powerful that there can be no peace if it is simultaneously in the possession of any two powers unless these two powers are bound by an indissoluble political union…. It will hardly be possible to get political action along that line unless high efficiency atomic bombs have actually been used in this war and the fact of their destructive power has deeply penetrated the mind of the public.
President Harry Truman’s diaries during the Potsdam Conference, July-August, 1945: I thought of Carthage, Baalbek, Jerusalem, Rome, Atlantis, Peking, Babylon, Nineveh, Scipio, Ramses II, Titus, Herman, Sherman, Genghis Khan, Alexander, Darius the Great—but Hitler only destroyed Stalingrad—and Berlin. I hope for some sort of peace, but I fear that machines are ahead of morals by some centuries and when morals catch up perhaps there’ll be no reason for any of it.
Winston Churchill, summarizing later in his history of the Second World War: To avert a vast, indefinite butchery, to bring the war to an end, to give peace to the world, to lay healing hands upon its tortured people by a manifestation of overwhelming power at the cost of a few explosives, seemed, after all our toils and perils, a miracle of deliverance.
President Harry Truman’s diaries during the Potsdam Conference, July-August, 1945: We have discovered the most terrible bomb in the history of the world. It may be the fire destruction prophesied in the Euphrates Valley Era, after Noah and his fabulous Ark.…
This weapon is to be used against Japan between now and August 10th. I have told the Sec. of War, Mr. Stimson, to use it so that military objectives and soldiers and sailors are the target and not women and children. Even if the Japs are savages, ruthless, merciless and fanatic, we as the leader of the world for the common welfare cannot drop that terrible bomb on the old capital or the new…
He and I are in accord. The target will be a purely military one and we will issue a warning statement asking the Japs to surrender and save lives. I’m sure they will not do that, but we will have given them the chance. It is certainly a good thing for the world that Hitler’s crowd or Stalin’s did not discover this atomic bomb. It seems to be the most terrible thing ever discovered, but it can be made the most useful.
Physicist Luis Alvarez, after the bombs were dropped: What regrets I have about being a party to killing and maiming thousands of Japanese civilians this morning are tempered with the hope that this terrible weapon we have created may bring the countries of the world together and prevent further wars. Alfred Nobel thought that his invention of high explosives would have that effect, by making wars too terrible, but unfortunately it had just the opposite effect.
Secretary of Commerce Henry Wallace, after both bombs were dropped and it still remained possible to drop more: Truman said he had given orders to stop the atomic bombing. He said the thought of wiping out another 100,000 people was too horrible. He didn’t like the idea of killing, as he said, “all those kids.
From an Interim Committee Scientific Panel to the Secretary of War Henry Stimson, delivered August 17, 1945: We are convinced that weapons quantitatively and qualitatively far more effective than now available will result from further work on these problems. The development, in the years to come, of more effective atomic weapons, would appear to be a most natural element in any national policy of maintaining our military forces at great strength; nevertheless we have grave doubts that this further development [of the hydrogen bomb] can contribute essentially or permanently to the prevention of war. We believe that the safety of this nation—as opposed to its ability to inflict damage on an enemy power—cannot lie wholly or even primarily in its scientific or technical prowess. It can be based only on making future wars impossible. It is our unanimous and urgent recommendation to you that, despite the present incomplete exploitation of technical possibilities in this field, all steps be taken, all necessary international arrangements be made, to this one end.
Physicist Arthur Compton, a month after the atomic bombs were dropped on Japan: We feel that this development [of the hydrogen bomb] should not be undertaken, primarily because we should prefer defeat in war to victory obtained at the expense of the enormous human disaster that would be caused by its determined used.
Physicist Edward Teller, late 1945, on the powerlessness of scientists in the face of more and more powerful weapons: If the development is possible, it is out of our powers to prevent it.
Physicist Robert Serber, on Robert Oppenheimer in late 1945: Oppie says that the atomic bomb is so terrible a weapon that war is now impossible.
Robert Oppenheimer, late 1945: …it is quite clear that the control of atomic weapons cannot be in itself the unique end of such operation. The only unique end can be a world that is united, and a world in which war will not occur.
Robert Oppenheimer, 1946: It did not take atomic weapons to make war terrible. It did not take atomic weapons to make man want peace, a peace that would last. But the atomic bomb was the turn of the screw. It has made the prospect of future war unendurable. It has led us up those last few steps to the mountain pass; and beyond there is a different country.
President Harry Truman in 1946, who felt that Robert Oppenheimer was a ‘cry baby’ scientist … [who] came to my office … and spent most of his time wringing his hands and telling me they had blood on them because of the discovery of atomic energy. 
Physicist Edward Teller, 1946: Nothing that we can plan as a defense for the next generation is likely to be satisfactory; that is, nothing but world-union.
President Harry Truman, 1948: I don’t think we ought to use this thing unless we absolutely have to. It is a terrible thing to order the use of something like that [here he looked down at his desk, rather reflectively] that is so terribly destructive, destructive beyond anything we have ever had. You have got to understand that this isn’t a military weapon…. It is used to wipe out women and children and unarmed people, and not for military uses. So we have got to treat this differently from rifles and cannon and ordinary things like that…. You have got to understand that I have got to think about the effect of such a thing on international relations. This is no time to be juggling an atom bomb around.
Physicist Edward Teller, 1948: World government is our only hope for survival…. I believe that we should cease to be infatuated with the menace of this fabulous monster, Russia. Our present necessary task of opposing Russian should not cause us to forget that in the long run we cannot win by working against something. We must work for something. We must work for World Government.
President Harry Truman, 1949: This isn’t just another weapon, not just another bomb. People make a mistake when they talk about it that way…. Dave, we will never use it again if we can possibly help it.
President Harry Truman, 1949: I am of the opinion we’ll never obtain international control [of atomic energy]. Since we can’t obtain international control we must be strongest in atomic weapons.
Chemist Glenn Seaborg, 1949, on the development of the hydrogen bomb: Although I deplore the prospects of our country putting tremendous effort into this, I must confess that I have been unable to come to the conclusion that we should not.
Remarks from a 1952 panel on nuclear disarmament, which included Robert Oppenheimer, Vannevar Bush, Allen Dulles, McGeorge Bundy, and others: Fundamentally, and in the long run, the problem which is posed by the release of atomic energy is a problem of the ability of the human race to govern itself without war. There is no permanent method of excising atomic energy from our affairs, now that men know how it can be released. Even if some reasonably complete international control of atomic energy should be established, knowledge would persist, and it is hard to see how there could be any major war in which one side or another would not eventually make and use atomic bombs. In this respect the problem of armaments was permanently and drastically altered in 1945.
President Harry Truman, before leaving office, 1953: War today between the Soviet empire and the free nations might dig the grave not only of our Stalinist opponents, but of our own society, our world as well as theirs…. The war of the future would be one in which man could extinguish millions of lives at one blow, demolish the great cities of the world, wipe out the cultural achievements of the past—and destroy the very structure of a civilization that has been slowly and painfully built up through hundreds of generations. Such a war is not a possibly policy for rational men.
Hartley Rowe, engineer and member of the General Advisory Committee on the hydrogen bomb, 1954: It was a pretty soul-searching time, and I had rather definite views…. I may be an idealist, but I can’t see [how] … any people can go from one engine of destruction to another, each of them a thousand times greater in potential destruction, and still retain any normal perspective in regard to their relationships with other countries and also in relationship with peace…. If a commensurate effort had been made to come to some understanding with the nations of the world, we might have avoided the development….
Physicists Enrico Fermi and I. I. Rabi, in the 1954 GAC report: Necessarily such a weapon goes far beyond any military objective and enters the range of very great natural catastrophes. By its very nature it cannot be confined to a military objective but becomes a weapon which in practical effect is almost one of genocide.
It is clear that the use of such a weapon cannot be justified on any ethical ground which gives a human being a certain individuality and dignity even if he happens to be a resident of any enemy country. It is evident to us that this would be the view of peoples in other countries. Its use would put the United States in a bad moral position relative to the peoples of the world.
Any postwar situation resulting from such a weapon would leave unresolvable enmities for generations. A desirable peace cannot come from such an inhuman application of force. The postwar problems would dwarf the problems which confront us at present.
The fact that no limits exist to the destructiveness of this weapon makes its very existence and the knowledge of its construction a danger to humanity as a whole. It is necessarily an evil thing considered in any light. For these reasons, we believe it important for the President of the United States to tell the American public and the world that we think it is wrong on fundamental ethical principles to initiate the development of such a weapon.
President Dwight Eisenhower, 1954, responding to criticism from South Korea at not using atomic weapons on North Korea: There is no disposition in America at any time to belittle the Republic of Korea. But when you say that we should deliberately plunge into war, let me tell you that if war comes, it will be horrible. Atomic war will destroy civilization. It will destroy our cities. There will be millions of people dead. War today is unthinkable with the weapons which we have at our command. If the Kremlin and Washington ever lock up in a war, the results are too horrible to contemplate. I can’t even imagine them. But we must keep strong…. I assure you that we think about these things continuously and as seriously as you do. The kind of war that I am talking about, if carried out, would not save democracy. Civilization would be ruined, and those nations and persons that survived would have to have strong dictators over them just to feed the people who were left. That is why we are opposed to war.
Physicist Neils Bohr, late 1950s: We are in a completely new situation that cannot be resolved by war.
 Richard Rhodes, The Making of the Atomic Bomb, 11
 Ibid., 312
 Ibid., 308
 Ibid., 141
 Ibid., 369
 Kai Bird and Martin J. Sherwin, American Prometheus: The Triumph and Tragedy of J. Robert Oppenheimer, and Martin J. Sherwin, American Prometheus: The Triumph and Tragedy of J. Robert Oppenheimer, 293
 Ibid., 289
 Richard Rhodes, The Making of the Atomic Bomb, 687-8
 Ibid., 697
 Ibid., 508-9
 Ibid., 683
 Ibid., 697
 Ibid., 690-1
 Richard Rhodes, Dark Sun: The Making of the Hydrogen Bomb, 18
 Richard Rhodes, The Making of the Atomic Bomb, 743
 Ibid., 751
 Kai Bird and Martin J. Sherwin, American Prometheus: The Triumph and Tragedy of J. Robert Oppenheimer, 418
 Richard Rhodes, Dark Sun: The Making of the Hydrogen Bomb, 208
 Kai Bird and Martin J. Sherwin, American Prometheus: The Triumph and Tragedy of J. Robert Oppenheimer, 317
 Richard Rhodes, The Making of the Atomic Bomb, 762
 Ibid., 778
 Richard Rhodes, Dark Sun: The Making of the Hydrogen Bomb, 205
 Richard Rhodes, The Making of the Atomic Bomb, 765
 Richard Rhodes, Dark Sun: The Making of the Hydrogen Bomb, 327
 Richard Rhodes, The Making of the Atomic Bomb, 766
 Richard Rhodes, Dark Sun: The Making of the Hydrogen Bomb, 344
 Ibid., 363
 Ibid., 395
 Ibid., 588
 Ibid., 583
 Ibid., 397
 Ibid., 401-2
 Ibid., 584
 Richard Rhodes, The Making of the Atomic Bomb, 532