There remains one (at least) theoretical and historical problem to confront with respect to Elsey’s argument that use of the bomb was foreordained, that it formed not a break but a continuum with the recent past practice of killing civilians from the air. In his June 1945 plea to arrange a non-combat demonstration of the bomb on a deserted island, James Franck pointed out that the American public, apparently, believed there was a threshold of horror beyond which certain weapons ought to be prohibited for use, even against an enemy widely regarded as subhuman. The American people, Franck insisted, drew the line at using poison gas in East Asia. This was true, ‘even though gas warfare is in no way more “inhuman” than the war of bombs and bullets.’ A few military officials and those in charge of the government’s Chemical Warfare Services in fact urged that gas or other chemical or biological agents be used to rout the Japanese from their Pacific island strongholds or against the home islands. Following Iwo Jima, the CWS proposed to the Joint Chiefs the use of chemical weapons on Okinawa, but the matter ended there. The subsequent struggle made several of the generals reconsider. General Joseph W. Stilwell, who had fought the Japanese in China, wanted George Marshall to permit the use of chemicals should it come to an invasion of Japan, and General Douglas MacArthur and Brigadier General William A. Borden both offered qualified support for deploying poison gas. Marshall himself, a decent man who, it may be recalled, had private doubts about dropping atomic bombs, raised the subject on 29 May 1945, with Stimson and Assistant Secretary of War John J. McCloy. Shaken by the tenacity of Japanese units on Okinawa, the Chief of Staff suggested developing ‘new weapons and tactics’ to overcome the ‘last ditch defense tactics of the Japanese’. Marshall proposed the use of mustard gas, the specter of Ypres in 1917. McCloy was willing to study the proposal, with an eye toward a public growing daily more alarmed at rising American casualties. Stimson could not stomach it. Neither could William Leahy, chairman of the Joint Chiefs and Truman adviser, who pointed out that Roosevelt had made public statements against the use of chemicals that were ‘beyond the probability of change’. There is no evidence that Truman sympathized with one side or the other in this debate; in the event, the United States used no chemical or biological weapons against the Japanese.66
Why not? Why atomic bombs but no mustard gas? There are several reasons. First, the military branches regarded the use of chemical agents as unprofessional, even unsporting, in a way that dropping bombs or firing explosive shells was not. The Navy and Army Air Force especially also believed they might find themselves starved of their preferred weapons and resources should chemicals be authorized for use in island warfare. Institutional rivalry thus to some extent trumped a willingness to fight with absolutely no restraint. Second, and unlike atomic weapons, gas had a history of use in combat, and fairly or not a particularly ugly reputation among both military and civilian constituencies. The world had recoiled in revulsion when gas was used in the First World War; not only was American public opinion unreconciled to its use in 1945 but so was the international community, several of its European members having experienced the release of chemical agents first hand. If not absolute, prohibitions nevertheless existed on the use of gas, while no treaty or arrangements yet governed nuclear weapons. Finally, and most important, the resistance to using gas had much to do with the way in which gas killed. As noted earlier, death from explosion and fragment and fire—from outside in, as it were—was more readily countenanced than death by an insidious agent that might enter the body undetected and then kill from the inside out. Death by gas was a violation of the body, unfair in a way that bombing (bizarrely) was not. The difference was even partly aesthetic, with trauma by explosion held more bearable than an end brought on by slow suffocation. Small comfort, perhaps, but the general abdication of conscience undergone by the world’s citizenry had not altogether eradicated its scruples concerning chemical and biological weapons.67
An odd coda: just after Harry Truman’s final speech to the nation as president in mid-January 1953, Atomic Energy Commissioner Thomas Murray wrote seeking reassurance that Truman did not regard the use of atomic weapons as ‘immoral’. Truman responded: ‘I rather think you have put a wrong construction on my approach to the use of the Atomic bomb. It is far worse than gas and biological warfare because it affects the civilian population and murders them by the wholesale.’68
Carried by an aging and ill-fated cruiser called the Indianapolis, the carefully cosseted core of the world’s first combat atomic bomb had arrived on Tinian on 26 July, the day of the Potsdam Declaration. It was joined to the rest of the bomb assembly on 1 August in an air-conditioned hut. When finished, Little Boy looked like ...a bomb. It was 14 feet long, 5 feet in diameter, and it weighed approximately 10,000 pounds. Its proximity fuse, set for an altitude of about 1,800 feet, was designed to touch off a small explosion at the rear of the bomb, which would send a uranium bullet hurtling toward the bomb’s nose. There it would collide with a ‘cap’ of fraternal U-235. If all went as planned, that would ignite an atomic explosion that would destroy the center of Hiroshima and transform the world.69