The First War of Physics (45 page)

Colonel Paul Tibbets joined the Target Committee meeting in Washington. Tibbets had served as a personal pilot to Dwight D. Eisenhower and had a reputation as the best pilot in the US Army Air Force. He had been selected to command a special air combat group, the 509th Composite Group, assembled specifically to provide a combat delivery system for the atomic bomb.
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He was scheduled to fly the converted B-29 that would deliver Little Boy to its target. His crews had been training in Cuba, gaining experience flying with heavy loads over water. Movement orders for the 509th had been issued in April, and an advance party had arrived at North Field, on Tinian Island in the northern Pacific, just ten days before on 18 May.

The uneasiness that had settled on the Los Alamos and Met Lab physicists was to a large extent shared by Stimson. He, too, was brooding over what the advent of atomic weapons might mean for the future security of mankind.

Stimson was 77 years old, and had been appointed a US Attorney in 1909 by Theodore Roosevelt, Franklin’s fifth cousin. He possessed a strong sense of morality, of faith in humanity and international law. He was horrified by the way that war on such an unprecedented scale had blunted this sense of morality among the Western democracies. The Allied firebombings of Dresden, Hamburg, and then of selected Japanese cities, represented a kind of total war that he disliked intensely. He was determined, somehow, to use the atomic bomb in a way that would minimise civilian casualties. ‘The reputation of the United States for fair play and humanitarianism,’ he said to Truman, ‘is the world’s biggest asset for peace in the coming decades. I believe the same rule of sparing the civilian population should be applied, as far as possible, to the use of any new weapon.’

At the very least, the former ancient capital city of Kyoto, a major cultural centre, should be spared. Stimson had spent his honeymoon there. Groves, for once, was out-manoeuvred. Kyoto was dropped from the target list.

Interim Committee

To address some of the post-war issues surrounding the use of atomic weapons, with Truman’s blessing Stimson had set up an Interim Committee, so called because it represented a temporary stop-gap for a permanent policy organisation to be established by the US Congress or international treaties. Its task was to develop the American position on the use of atomic weapons in wartime, and debate some aspects of post-war atomic policy, including international control. The idea had come originally from Bush and Conant. Stimson was chairman, and Bush, Conant, MIT president Karl Compton (Arthur Compton’s brother), Assistant Secretary of State William Clayton, Undersecretary of the Navy Ralph Bard and Stimson aide George L. Harrison were appointed as members. Byrnes was a late addition. At the Interim Committee’s first meeting it was recognised that the Manhattan Project scientists might themselves have an important contribution to make, and Arthur Compton, Lawrence, Fermi and Oppenheimer were recommended for appointment to a scientific panel.

Separate briefings by Stimson and Groves and the first few meetings of the Interim Committee gave Byrnes the background he needed. The first full meeting of the committee and its scientific panel was held at the Pentagon on 31 May. Army Chief of Staff General George C. Marshall, Groves and a couple of aides were also invited to attend.

Individual committee members quickly established their own positions. On the subject of control and inspection, Oppenheimer argued for free exchange of atomic information, with emphasis on the peace-time uses of atomic power, preferably before the bomb was actually used. This, he suggested, would greatly strengthen America’s moral position. His unspoken desire was, no doubt, to see that the ultimate legacy of the Manhattan Project, and his own legacy as scientific director of Los Alamos,
should be the enlargement of human welfare rather than weapons of mass destruction.

But free exchange of information raised questions concerning the nature of an international control organisation required to police the uses to which such information might be put. Stimson was not sure: ‘The Secretary asked what kind of inspection might be effective and what would be the position of democratic governments as against totalitarian regimes under such a program of international control coupled with scientific freedom.’ Totalitarian regimes were not, after all, noted for their commitment to the strict terms of international agreements. At issue, of course, was the anticipated behaviour of the Soviet Union.

Oppenheimer had faith in Russia’s scientists, and pointed out that Russia had always been very friendly to science. Perhaps the Soviet Union could be approached in a tentative fashion and be advised of the Manhattan Project in the most general terms in the hope of securing their co-operation. His statement dimly echoed his August 1943 conversation with Pash and Johnson. Back then he had said that he would not want classified atomic information to get to the Soviets through the ‘back door’. Now he was looking for a front door, for a step towards Bohr’s ‘open world’.

He found an unexpected ally in Marshall, who argued that the intransigence of the Soviets was more often imagined than real. When real, their lack of co-operation derived from their understandable concern for their own security. ‘General Marshall was certain that we need have no fear that the Russians, if they had knowledge of our project, would disclose this information to the Japanese. He raised the question whether it might be desirable to invite two prominent Russian scientists to witness the [Trinity] test.’

Had Churchill been present at this discussion, it is not difficult to imagine his reaction to Marshall’s proposal. Churchill was not present, but Byrnes was. ‘Mr Byrnes expressed a fear that if information were given to the Russians, even in general terms, Stalin would ask to be brought into the partnership. He felt this to be particularly likely in view of our commitments and pledges of cooperation with the British … [He] expressed the view, which was generally agreed to by all present, that the most desirable
program would be to push ahead as fast as possible in production and research to make certain that we stay ahead and at the same time make every effort to better our political relations with Russia.’

It was a familiar formula, one which effectively bolted the door that Oppenheimer was trying to prise open. Byrnes thought he understood enough about the atomic bomb to interpret the American lead in atomic weapons technology as a powerful bargaining chip in post-war US–Soviet relations. In other words, he had not understood the bomb at all. Pushing ahead in production and research could have only one consequence. And this was not the one he intended.

The meeting adjourned for lunch and resumed again at 2:15pm. Of the morning participants, only Marshall was now absent. The discussion over lunch had switched to the impending use of the bomb against Japan, and this discussion continued as the meeting resumed.

If growing moral qualms affected any of the members of the Interim Committee, these are not reflected in the notes of the meeting. The only issue debated at length concerned the psychological impact of the bomb. The opinion was expressed that the impact of one bomb might not be much different than the impact of current firebombing raids on Japanese cities.

As there was still considerable uncertainty over the yield of an atomic bomb (Compton had earlier estimated an explosive force anywhere between 2,000 and 20,000 tons of TNT), Oppenheimer did not argue with the observation. ‘However, Dr Oppenheimer stated that the visual effect of an atomic bombing would be tremendous. It would be accompanied by a brilliant luminescence which would rise to a height of 10,000 to 20,000 feet. The neutron effect of the explosion would be dangerous to life for a radius of at least two-thirds of a mile.’
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After further discussin of various types of targets, Stimson summarised the committee’s interim conclusions:

The Secretary expressed the conclusion, on which there was general agreement, that we could not give the Japanese any warning; that we could not concentrate on a civilian area; but that we should seek to make a profound psychological impression on as many of the inhabitants as possible. At the suggestion of Dr Conant the Secretary agreed that the most desirable target would be a vital war plant employing a large number of workers and closely surrounded by workers’ houses.

It was not much of a compromise. Stimson wanted to avoid unnecessary civilian casualties, but the entire population of Japan had in effect been drafted in support of the war effort. In Japan, bombing a war plant closely surrounded by workers’ houses meant bombing men, women and children. Without warning.

Oppenheimer had argued at Los Alamos that the war should not end without the world knowing about the bomb and its effects. The Manhattan Project had to be at least driven to the point where the bomb could be tested. His scientists had been persuaded, even pacified. But Oppenheimer had not explained that this would mean bombing a large number of workers and their families without warning. Yet this is what he was now accepting.

It seems that nobody at the meeting thought to raise the question about possible psychological impacts on the Soviets.

Groves had been fairly quiet throughout, at least according to the formal meeting notes. As the meeting wound to a close, Groves took the opportunity to raise the issue of certain troublesome scientists, ‘of doubtful discretion and uncertain loyalty’, who had plagued the atomic programme since its inception. Groves was aware of Szilard’s meeting with Byrnes and his attempts to influence the conclusions of the Interim Committee, and there can be no doubt about the identity of the scientist he had in mind. The committee agreed that nothing could be done until after the bomb had been tested or used, at which point ‘steps should be taken to sever these scientists from the program’.

Oppenheimer remained silent.

The Franck report

The four members of the scientific panel agreed to meet again at Los Alamos on 16 June to finalise their formal recommendations on the use of the bomb. They were forbidden from revealing details of the membership of the Interim Committee or the conclusions that had been reached thus far, but on his return to Chicago, Compton told the Met Lab scientists that their views would be welcome. If the scientists could prepare submissions in the next two weeks, he would convey them to the scientific panel at its next meeting.

Compton’s invitation now sparked a flurry of activity. The Met Lab scientists formed themselves into groups to review future atomic organisations, research, education and security, production of atomic materials, and the political and social problems posed by the bomb. Szilard was asked to chair the group on production, but declined. He preferred to focus on his contribution as a member of the political and social problems group under the chairmanship of James Franck, with whom Oppenheimer had once worked in Göttingen. The group also included Glenn Seaborg and Russian-born biophysicist Eugene Rabinowitch.

It was Rabinowitch who drafted the group’s report, but Szilard’s ghost lies beneath many of its words. The report is forthright in establishing the most logical consequence of American attempts to maintain supremacy in nuclear armaments:

[A]ll that these advantages can give us, is the accumulation of a larger number of bigger and better atomic bombs – and this only if we produce those bombs at the maximum of our capacity in peace time, and do not rely on conversion of a peace time nucleonics industry to military production after the beginning of hostilities. However, such a quantitative advantage in reserves of bottled destructive power will not make us safe from sudden attack. Just because a potential enemy will be afraid of being ‘outnumbered and outgunned,’ the temptation for him may be overwhelming to attempt a sudden unprovoked blow –
particularly if he would suspect us of harboring aggressive intentions against his security or ‘sphere of influence.’

To avoid an arms race it would be necessary to exercise remarkable self-restraint:

From this point of view a demonstration of the new weapon may best be made before the eyes of representatives of all United Nations, on the desert or a barren island.
The best possible atmosphere for the achievement of an international agreement could be achieved if America would be able to say to the world, ‘You see what weapon we had but did not use. We are ready to renounce its use in the future and to join other nations in working out adequate supervision of the use of this nuclear weapon.’ … If the United States would be the first to release this new means of indiscriminate destruction upon mankind, she would sacrifice public support throughout the world, precipitate the race of armaments, and prejudice the possibility of reaching an international agreement on the future control of such weapons.

By now wary of the formal channels of communication with senior politicians, Franck himself sought to bring a copy of his report directly to the attention of Secretary Stimson. Compton met him in Washington, but they were told that Stimson was out of the city (he was not). Stimson’s aide, Harrison, assured them that he would pass the report on. Compton hastily drafted a covering note. ‘In this note it was necessary for me to point out that the report, while it called attention to difficulties that might result from the use of the bomb, did not mention the probable net saving of many lives, nor that if the bomb were not used in the present war the world would have no adequate warning as to what was to be expected if war should break out again.’ Compton thus undermined the report even as he helped Franck seek attention for it. Franck’s report was immediately classified.

A few days later, Compton carried the report to the meeting of the scientific panel at Los Alamos and passed copies to Oppenheimer, Lawrence
and Fermi. To men more accustomed to drawing testable conclusions from their evaluation of established scientific facts, the political conclusions they now had to draw from complex political and military uncertainties must have seemed daunting.

It is likely that Compton himself argued that the unannounced use of the bomb against Japan would swiftly end the war and save countless American lives. Japan was defeated but prized its honour as a nation above all else. ‘In spite of such disastrous damage,’ Compton later wrote, ‘the Japanese militarists seemed … unwavering in their determination to fight to the finish.’ The Japanese military culture promoted suicide as preferable to the shame of defeat, as witnessed by the kamikaze attacks on Allied destroyers, which peaked in the battle of Okinawa in April. Compton’s brother Karl, a director of the Office of Field Service of the OSRD, had recently departed for Manila to oversee the provision of radar support ahead of the planned American invasion and occupation of Japan. Compton hoped that use of the bomb might render invasion unnecessary.