War of Nerves

by Jonathan Tucker

  Attending the May 15 conclave at Wolf’s Lair were Albert Speer, the Minister of Armament and War Production; Field Marshal Wilhelm Keitel, the supreme commander of the Wehrmacht; Brigadier General Walther Schieber, who oversaw the chemical industry for the Speer ministry; and other senior military officials and directors. Otto Ambros, IG Farben’s leading expert on poison gases, was also present. He had received a telegram from Speer a few days earlier ordering him to come to Berlin, whence he had flown in an official airplane to Rastenburg.

  The last item on the agenda of the daylong war conference was a one-hour discussion of the situation in the chemical weapons field. Speer and Schieber began by describing Germany’s readiness for waging gas warfare and the likelihood that the Allies would resort to such weapons. Then Ambros took the floor and reported objectively on the production of war gases, referring to a table that described the Wehrmacht’s military requirements for the various agents and the existing stockpiles. Ambros noted that, thanks to the outstanding work of IG Farben scientists, Germany had developed a new class of war gases that targeted the nervous system and were best described as “nerve agents.” The first such compound, Tabun, could kill in minute doses, while a second agent called Sarin was six times more potent. Because of their extraordinary lethality, the use of these gases would have a severely demoralizing effect on the enemy.

  As of May 1, 1943, Ambros said, Germany had produced a total of 44,764 metric tons of chemical warfare agents, including 1,500 tons of Tabun. Moving from pilot- to industrial-scale production of Tabun had been extremely challenging because the manufacturing process involved highly toxic and corrosive materials. “Nevertheless,” Ambros added, “in the past few months, remarkable progress has been achieved.” Although the level of Tabun production at Dyhernfurth at that time was 350 metric tons per month, Anorgana expected to reach the full capacity of 1,000 tons per month in early 1944. The company also planned to construct a Sarin pilot plant at Dyhernfurth with a capacity of 100 tons per month. Ambros concluded by urging Hitler to allocate more resources to the chemical weapons sector, including manpower for construction and operations, materials for buildings and installations, and air defenses to protect the major storage depots.

  Hitler was clearly disappointed by this report, noting that for most types of chemical warfare agents, not even half the requirements of the General Staff had been achieved. He then asked about the enemy’s chemical warfare capabilities and Germany’s relative strength in this area. Ambros replied that although the Wehrmacht possessed all of the major choking and blister agents, the enemy had larger stockpiles and production capacity. Any industrial power that could manufacture petrochemicals such as ethylene oxide was capable of mass-producing mustard. “I believe,” Ambros added, “that the enemy, because of his greater supplies of ethylene, probably has the capacity to produce larger quantities of mustard than does Germany.”

  Hitler’s toothbrush mustache bristled with irritation. “I understand that countries that have oil are in a better position to make mustard,” he snapped, “but what about the special gas Tabun? I have been told that in this area Germany has a monopoly. Do you believe that the enemy has also developed nerve agents?”

  Aware of Hitler’s dangerous temper, Ambros chose his words carefully. Whether Germany had a monopoly in the nerve agents could not be judged with any certainty, he said. German scientific papers and patents on related compounds had been published in the open scientific literature as early as 1902, and only much later had these materials been classified and withdrawn from commercial development. It was therefore possible that the enemy had developed nerve agents like Tabun. “I am also convinced,” Ambros added, “that in the event that Germany were to use this special gas, other countries would not only be able to imitate it quickly but could produce it in considerably larger quantities.”

  Visibly distressed by this remark, Hitler turned abruptly on his heels and strode out of the room.

  AMBROS’S BELIEF that the Allies had independently discovered Tabun or related compounds was based largely on inference. He was aware that German intelligence had surveyed the U.S. chemical literature before the war and found published papers on compounds whose chemical structure was distantly related to Tabun. Since the war began, all such information had disappeared from U.S. scientific journals, suggesting that the research had become classified. German intelligence was also familiar with the famous Soviet school of organophosphorus chemistry led by Professor Alexander E. Arbusov in the Russian city of Kazan. Schrader had used a reaction sequence developed by Arbusov to synthesize an intermediate in the production of Sarin.

  In fact, Ambros had overestimated the extent of the Allies’ progress. Although American, British, and Soviet chemists were studying various organophosphate agents and assessing their military potential, they had not independently discovered Tabun or Sarin. Beginning in 1941, a chemistry professor at the University of Cambridge named Bernard Charles Saunders had synthesized several fluoride-containing organophosphate compounds, of which the most promising was diisopropyl fluorophosphate, or DFP. (Saunders was unaware that the German chemist Willy Lange had previously synthesized DFP in 1932.) In addition to being quite toxic, DFP had desirable physical properties and was cheap and easy to manufacture. Saunders conducted a series of risky experiments on himself and his colleagues in which he used a bicycle pump attached to a round-bottom flask to disperse low concentrations of DFP in a sealed room. The scientists then entered the room and cautiously sniffed the air to assess the agent’s physiological effects.

  On December 11, 1941, Saunders reported to the British Ministry of Supply, which was responsible for chemical weapons development, that high levels of DFP had a rapid “knockout” action comparable to that produced by hydrogen cyanide. At much lower doses, DFP constricted the pupils of the eyes, resulting in a marked dimming and impairment of vision that could put enemy soldiers out of action for an extended period. British officials considered the new agent promising enough to commission the Chemical Warfare Establishment at Sutton Oak, England, to develop a small-batch production plant. It gradually became clear, however, that DFP did not offer a significant improvement in toxicity over standard agents such as mustard or phosgene, making it chiefly of interest as a harassing agent.

  The British shared their findings on DFP with American military chemists working in Division 9 of the National Defense Research Committee (NDRC), a wartime agency reporting to the U.S. Office of Scientific Research and Development led by Dr. Vannevar Bush. From December 1942 to the end of 1945, the NDRC issued contracts to academic chemists at the University of Illinois, the University of Chicago, and the California Institute of Technology to synthesize and evaluate roughly two hundred different organophosphorus compounds, many of them containing fluorine, yet none approached the toxicity of Tabun or Sarin. The U.S. Chemical Warfare Service was sufficiently interested in DFP (which the Americans called PF-3) to contract with the Monsanto Corporation’s Phosphate Division to build a pilot production plant and to conduct some tests with the agent on soldiers at Edgewood Arsenal. But although test runs of the pilot plant produced 535 pounds of DFP for testing purposes, the Army decided not to stockpile it as a standard agent. Other U.S. wartime chemical research focused on the development of insecticides to combat malaria mosquitoes and other vectors of infectious disease. (A common misconception holds that DDT, a powerful insecticide discovered by the Swiss chemist Paul Hermann Müller in 1939, was related to the German nerve agents. In fact, DDT is a chlorinated hydrocarbon whose chemical structure has nothing in common with Tabun or Sarin.)

  In a broader sense, however, Ambros’s calculation was correct. If the Germans had employed Tabun or Sarin during the war and the Allies had obtained samples of the new agent, ongoing British and American research on DFP and related substances would have enabled those countries to identify the structure of Tabun and replicate its synthesis in a fairly short time. The Allies would then have launched a wartime crash program to
mass-produce the new agent. Scaling up from the laboratory bench to industrial production would have been difficult and time-consuming, but still feasible with a sufficient investment of money and effort. Thus, any German military advantage arising from the first use of nerve agents would have been short-lived, and the consequences for the German population severe, given the inadequate gas protection of most civilians and the Allies’ growing air superiority.

  Hitler also knew that even if the Allies did not possess nerve agents, they did have vast stockpiles of aerial bombs filled with phosgene and mustard agent with which to retaliate against German cities. Indeed, Allied leaders made explicit threats to deter the German use of chemical weapons. In June 1943, President Franklin D. Roosevelt declared that the United States would under no circumstances resort to chemical weapons unless they were used by the enemy first. But he then warned, “Any use of gas by any Axis power will immediately be followed by the fullest possible retaliation upon munition centers, seaports, and other military installations through the whole extent of the territory of such Axis country.”

  To ensure German superiority in the event that chemical weapons were used, Ambros recommended the immediate expansion of production capacity for both Tabun and Sarin. This argument fell on receptive ears, and on May 26, 1943, only ten days after the meeting at Wolf’s Lair, Hitler ordered the doubling of Tabun production at Dyhernfurth from 1,000 to 2,000 metric tons per month by the end of 1944, and an increase in Sarin output from 100 to 500 tons per month. Hitler and Speer also approved Anorgana’s request for more resources for nerve agent manufacture, including 88 million reichsmarks, 55,000 tons of steel, and 6,900 additional workers.

  Despite continued pressure from Bormann, Goebbels, and Ley, however, Hitler showed no inclination to initiate gas warfare against the Soviet Union. Fearing that even a limited use of chemical weapons might trigger massive Allied retaliation, he ordered that no chemical munitions were to be transported outside the Reich, including Bohemia and parts of Poland, or deployed to the Russian front. Tight control over the chemical stockpile would reduce the risk of unauthorized use and avoid the capture of the weapons by enemy forces.

  In early November 1943, Ambros informed the Army Ordnance Office that because of shortages of raw materials such as phosphorus, chlorine, and sodium cyanide, it would not be possible to double the production of Tabun at Dyhernfurth by the end of 1944 as planned. In fact, production of Tabun never approached the ambitious goal of 2,000 tons per month; the maximum output was about 800 tons per month of the 80 percent formulation. In order to increase the rate of Tabun production, Anorgana expanded the number of forced laborers at Dyhernfurth. A second satellite labor camp for up to 3,000 prisoners was completed in the fall of 1943, with plans to increase the total number to 9,700. The inmates were housed in thirty drafty barracks, poorly clothed and fed, and forced to work twelve hours a day. Between twenty and thirty prisoners died each week from malnutrition, beatings, exhaustion, and presumably Tabun exposure. To preserve the secrecy surrounding nerve agent production at Dyhernfurth, forced laborers who tried to escape were summarily executed. In any event, few inmates could expect to live long enough to tell the outside world about their experiences.

  Because of the operational drawbacks of Tabun, which decomposed during storage and did not vaporize at low temperatures, Ambros wished to give priority to the manufacture of Sarin, which was both more toxic and more volatile. But construction of the Sarin production facility at Dyhernfurth was far behind schedule. Although the Luranil construction company had broken ground for the second Sarin plant at Falkenhagen in September 1943, difficulties in obtaining building materials and skilled labor meant that production was unlikely to start until the middle of 1945. Ambros had assigned his protégé, a young IG Farben chemist and SS officer named Jürgen von Klenck, to be the future director of the Falkenhagen plant, despite his lack of experience.

  IN APRIL 1944, Hitler made his personal surgeon, Dr. Karl Brandt, responsible for protecting the German civilian population against an Allied chemical attack. Brandt had enjoyed a remarkable career under the Nazi regime. His wife had been Hitler’s swimming instructress, and while on holiday in Bavaria in 1932, the couple had visited the Nazi leader’s country retreat, a rustic villa called Berghof on the Obersalzberg mountain near Berchtesgaden. During the visit, Hitler’s entourage was involved in an automobile accident, injuring his adjutant and three relatives. Brandt skillfully treated their injuries and gained Hitler’s gratitude and affection shortly before the Nazi seizure of power in January 1933. The following year, at the age of twenty-eight, Brandt became Hitler’s personal surgeon and accompanied him to Venice for a summit meeting with Mussolini. Later that year Brandt joined the SS, and in the summer of 1942 he was appointed General Commissioner for Reich Medical Services with the rank of colonel.

  In his new position as Special Commissioner for Gas Defense, Brandt was responsible for shielding the German population against chemical attack. Of the 68 million inhabitants of the German Reich, few were equipped with effective chemical protective gear. Beginning in 1938, some 30 million respirators had been produced and issued, but only about half were still in good working order. Brandt planned to implement a program for the manufacture of 45 million “people’s gas masks” (Volksgasmasken), incorporating a filter made of activated charcoal. Although a plan for mass production of the masks was drawn up, German industry was already working at full capacity and key materials such as rubber were in short supply. The resulting delay in production meant that the populations of major German cities remained vulnerable to Allied chemical attack.

  Also during the spring of 1944, Richard Kuhn, working at the Kaiser Wilhelm Institute in Heidelberg, made a striking discovery. He was continuing his research for the German Army by screening a wide variety of organophosphorus compounds—some of which he had synthesized himself—for the ability to inhibit cholinesterase. Because of the Nazi obsession with secrecy, his research was “compartmented”: he was not put into contact with other scientists in the nerve agent field and was completely unaware of Schrader’s work. When Kuhn replaced the isopropyl alcohol used to make Sarin with a more complex alcohol known as pinacolyl, the resulting substance (which he called Compound 25075) had a camphorlike odor and was roughly twice as potent as Sarin in inhibiting cholinesterase. The War Office code-named this new compound “Soman,” and Kuhn synthesized small amounts in the laboratory.

  Toxicological testing of Soman in animals by Dr. Gross at IG Elberfeld revealed that the new agent was twice as toxic as Sarin by inhalation, readily penetrated the skin, and passed rapidly from the bloodstream into the brain, enhancing its lethal effects. Even more striking, Soman inactivated cholinesterase irreversibly within two minutes, severely limiting the effectiveness of atropine as an antidote. Over the next several months, Kuhn and his colleagues tested about fifty analogues of Sarin and Soman for their ability to inhibit cholinesterase in his test-tube system. The most promising compounds were then tested on dogs and apes.

  Meanwhile, the war was reaching a major turning point—the Allied invasion of German-occupied France—in which a decision by Hitler to employ nerve agents could have a decisive impact on the outcome.

  CHAPTER FOUR

  TWILIGHT OF THE GODS

  SHORTLY AFTER DAWN on June 6, 1944 (D-Day), a huge armada of Allied warships approached the rainy, windswept coast of France and began disembarking thousands of landing craft filled with American, British, and Canadian soldiers. It was the start of Operation Overlord, the Allied invasion of German-occupied Europe. Under the cover of heavy fire from the battleships’ big guns, the troops crossed the choppy waves toward the Normandy beaches, facing a withering hail of machine-gun fire from German pillboxes on the cliffs above. Although the first waves of infantry suffered heavy losses, by afternoon the Americans had seized a portion of two beaches, and the British three.

  Commanding all American, British, Canadian, and French forces involved in Operation Over
lord was the Supreme Headquarters Allied Expeditionary Forces (SHAEF), which had been established in February 1944 under Major General Dwight D. Eisenhower. Before the Normandy landings, SHAEF military planners had worried that Hitler might employ chemical weapons in a desperate attempt to repel the invasion. Allied beachhead operations would be concentrated in a relatively small area, providing an ideal target for chemical attack, and many of the invading troops did not even carry gas masks. As General Omar Bradley noted in his 1951 memoir, A Soldier’s Story, “While planning the Normandy invasion, we had weighed the possibility of an enemy gas attack and for the first time speculated on the probability of his resorting to it. . . . I reasoned that Hitler, in his determination to resist to the end, might risk gas in a gamble for survival.”

  To deter the German use of chemical weapons, Roosevelt and Churchill warned of severe retaliation in kind and prepared to follow through with this threat. The two leaders ordered the stockpiling of a sixty-day supply of chemical bombs at depots in England and the training of air crews to deliver the weapons. In the event that the Germans unleashed a chemical attack, two Allied retaliatory operations could be mounted within forty-eight hours, each involving four-hundred-bomber formations that would deliver hundreds of tons of mustard and phosgene against German cities. Fortunately, the feared attack did not materialize. As General Bradley wrote in his memoir, “When D-Day finally ended without a whiff of mustard, I was vastly relieved. For even a light sprinkling of persistent gas on Omaha Beach would have cost us our foothold there.”