What was it about chemical weapons, and gas in particular, that made it the subject of special opprobrium by scientists and others after the war? It was not that gas killed more men more efficiently than other weapons, as the First World War casualty figures indicate. Gas-protection technology advanced quickly beyond Haldane’s urine-soaked sock, so that with enough warning and proper discipline soldiers in gassed trenches could remain undamaged. But there lingered what was called the ‘subjective effect’ of gas. In an English test of a lachrymator abbreviated SK in early 1915, an officer standing well upwind of a burst shell later complained of weakness and illness, despite his having done no more than observe the explosion. Haber explains the man’s fear as the product of an overactive imagination. That is precisely the problem with gas, or part of the problem: it insinuates itself into the atmosphere that people must breathe to live, thus destroying any idea of a boundary between what brings death and what sustains life. Unlike a bullet or a bomb, it kills quietly, insidiously, masquerading as something innocuous or even pleasant. ‘The English gas is almost odorless and can only be seen by the practised eye on escaping from the shell,’ recalled a German infantry officer. ‘The gas steals slowly over the ground in a blueish haze and kills anyone who does not draw his mask over his face as quick as lightning before taking a breath.’ Mustard gas smells like horseradish, though the Germans would later mask it with the scent of lilac. Phosgene bears a faint odor of cut grass and may not immediately affect those who breathe it; twelve hours later its victims’ lungs fail.20
Not only does gas refuse to acknowledge the elemental boundary between life and death: it also resists containment, and it is thus inherently indiscriminate. Infantry soldiers hated it when their own side attacked with gas, since a change in wind direction could reverse the direction of the cloud and envelop them. (A few of their officers thought the use of gas unsporting.) Civilians near the Western Front were increasingly subject to the vagaries of gas during 1916-18. Distribution of gas protection and information to local residents was haphazard in Belgium and France; during one particularly heavy German attack with mustard near Armentieres in July 1917, 86 civilians died and nearly 600 others were injured. Haber estimates conservatively—his figures include no Germans—that 5,200 civilians were poison-gas casualties during the First World War. By the war’s end, technicians were experimenting with a variety of ways to deliver gas so as to achieve the greatest and quickest effect, including the use of long-range artillery shells filled with gas and chemicals disbursed from airplanes. That the latter innovation was a likely feature of the next war was little disputed by scientists, novelists, and strategists of battle. American planners imagined attaching gas sprayers to the wings of aircraft. Others pictured gas bombs. Amos A. Fries, head of the US Chemical Warfare Service during and after the war, meant to reassure when he wrote (with Major C. J. West) in 1921: ‘As to noncombatants, certainly we do not contemplate using poisonous gas against them, no more at least than we propose to use high explosives in long range guns or aeroplanes against them.’ The nature of gas as a substance able to drift over distance and penetrate standard defenses of populations made it a terrible, logical weapon to envision as useful against civilians.21
There is also the matter of how gas kills. While burning and blinding are common injuries resulting from gas attacks, death from gas is most often caused by suffocation. Chlorine and phosgene are lung irritants. They inflame respiratory tissue, causing in it lesions and drawing fluid from elsewhere in the bloodstream, thus overwhelming the lungs with congestion. ‘In severe cases,’ writes Edward Spiers, ‘the victims die from asphyxiation, drowning in the plasma of their own blood.’ A British sergeant recalled seeing a dozen men gassed with chlorine in May 1915: ‘Their colour was black, green, and blue, tongues hanging out and eyes staring—one or two were dead, and others beyond human aid, some were coughing up green froth from their lungs. It is a hateful and terrible sensation to be choked and suffocated and unable to get breath: a casualty from gun fire may be dying from his wounds, but they don’t give him the sensation that his life is being strangled out of him.’ To be sure, dismemberment by explosive, multiple gunshot wounds, or burns from incendiary bombs are awful too, and horribly painful. But the thought of suffocation, slow and uncontrollable, touches the deepest place of human fear. It is a primal, helpless death, one of betrayal by the silent unbreathable air; it is slow, unheroic, panic-inducing, ugly. It is not unlike death by radiation.22
The scientists and soldiers who developed chemical weapons for their belligerent nations during the First World War seemed to establish a camaraderie one finds in those who come together for a noble cause. An interviewer once told Otto Hahn that he was surprised so many noted German chemists had joined the war effort in such dangerous work as gas provided. ‘Why?’, asked Hahn. ‘We volunteered, we offered our services.’ A British chemist recalled that ‘we were, with one or two exceptions, a band of brothers’, and French planners met frequently, if not always effectively, to coordinate offensive and defensive chemical strategy. They were professionals, called upon by their government to help protect soldiers and civilians. They were doing patriotic service, an argument that may have been especially meaningful to Fritz Haber, a Jew who was, according to his son, ‘well aware that his Jewish origin was both obstacle and spur’ to his loyalty. They could tell themselves—some did—that gas was far more likely to disable enemies than kill them, so it was an oddly humane weapon.
What the chemists and users of gas told themselves above all was that their weapon worked best if men and women perceived it to be horrible, because the graver the apparent threat from the weapon, the more likely an early concession by its victims. Leaders of warring nations, behaving rationally, like scientists, would seek to avoid national annihilation. Great danger of annihilation meant a shorter war. Amos Fries told a Senate committee just after the war that, the more ‘deadly’ the weapons, ‘the sooner... we will quit all fighting’. Make war terrible enough, and men would never start it. Haber had persuaded Hahn to work on gas—indeed, to throw himself ‘wholeheartedly’ into the work—by insisting that chemical weapons would end the war quickly. The use of gas would finally save lives.24
This was bold justification of weapons’ work, and probably believable on some level to those who advanced it. But most men cannot read about the results of their research crippling and killing other men without feeling remorse. Otto Hahn, who, unusually for a scientist, came face to face with Russian victims of a gas attack, confessed to feeling shame for his role in their deaths, but in the end ascribed them to ‘the senselessness of war’, not to human agency (and certainly not to his own). His boss, Fritz Haber, was confronted by his chemist wife, Clara, about the ‘barbarism’ of poison gas; it was, she insisted, ‘a perversion of science’. Not so, Haber remonstrated, rehashing arguments he had used earlier with Hahn. The night after their argument, Clara Haber took her life. After the war, Hahn related, Haber feared trial as a war criminal. He dropped out of sight for a while, then reappeared having grown a beard, in the hope of avoiding recognition.
There are many ways in which the development of chemical weapons differed significantly from the manufacture of an atomic bomb. The chemistry of gas was easier to master than the physics of the nucleus. Gas carries no powerful blast or searing fire, it is fickle when it is blown or burst into the air, and most of all it can be protected against, provided a targeted group has adequate notice and equipment. But the similarities between chemicals and nuclear weapons are sufficiently arresting to justify the lengthy consideration of gas offered here. Chemicals and atom bombs were in their times new weapons, understood by those who made them as things unprecedented and possibly decisive in war. Both chemicals and chain-reacting neutrons put weapons into a sinister dimension virtually beyond sight and sound: in trenches men blundered into undetectable pockets of gas, while radiation (following a blast that Hiroshimans, of course, saw and heard) worked its deadly way undetected into people who had apparently escaped harm. And both weapons, even in their preparation, killed scientists hideously, much as they would kill many others with their use on battlefields and over cities. In December 1914, Dr Otto Sackur, an associate of Fritz Haber, died when a tear-gas compound he was working on exploded. Marie Sklowdowska Curie, discoverer of the radioactive elements polonium and radium, died in 1934 of leukemia. She was by then nearly blind, and her fingers were twisted and burned from the radiation to which she had exposed herself in the laboratory. Sackur and Curie were early casualties of weapons once fanciful, then dreadful, and harbingers of far greater harm that would be visited on the world.26