The Nazi origins of deadly nerve gases

In 1943, the German Army Ordnance Office recruited Richard Kuhn to study nerve gas. Kuhn was an extraordinary chemist—he won the 1938 Nobel Prize in Chemistry for his efforts to understand the structure and function of vitamin B and carotene compounds. He was also an ardent Nazi, with a penchant for signing off his scientific presentations and correspondence with “Sieg Heil.” Kuhn and his colleagues were tasked with determining the mechanism by which nerve agents caused damage. They discovered that nerve agents block an enzyme called cholinesterase, which is responsible for breaking down acetylcholine, a neurotransmitter that is released into the synapses that connect nerve cells to other nerve cells or muscle cells during electrical signaling. When this enzyme is blocked, nerve cells in the brain and muscles are stuck in an overstimulated state, leading to a wide variety of symptoms including excessive sweating and salivation, pinpoint pupils, vomiting, seizures, and asphyxiation. As part of their research, Kuhn and colleagues synthesized a brand-new nerve agent, soman, which was twice as good as sarin at inhibiting cholinesterase.

From the start of WWII, some in the military were raring to dispatch their nerve weapons “on a very large scale against the enemy hinterland by air strikes,” noted German Colonel Hermann Ochsner in 1939. He said at the time: “There is no doubt that a city like London would be plunged into a state of unbearable turmoil that would bring enormous pressure to bear on the enemy government.” But Hitler demurred, even after Germany’s spectacular defeat at Stalingrad over the winter of 1942–43, which many believe was a turning point in the war. Why did Hitler veto their use?

Some historians point to the fact that Hitler had been a victim of chemical weapons—probably mustard gas—during WWI. As a result of this experience, Hitler believed using poison gas on the battlefield was unethical, an incredibly inconsistent position given his directive to use Zyklon B and other poisonous gases to kill millions of concentration camp prisoners. But it might not have been his personal experience that made Hitler stall on deploying nerve agents. The German Army had had enormous success with its Blitzkrieg strategy: fast and furious attacks using tanks and bombers, followed by foot soldiers. So the use of nerve agents by bombers would have contaminated the very area the army would have then had to occupy. There was also concern that the Allies had discovered the potent chemical weapons and would retaliate.

The Allies had no idea that the German military had discovered and was stockpiling a suite of extraordinarily toxic chemical weapons. But they could, and should, have known. In May 1943, after Germany lost a six-month battle in Tunisia, Allied forces took some 230,000 Axis soldiers prisoner. Among these prisoners of war was a German who informed British interrogators that he was a chemist who had worked at a secret chemical weapons institute—the Spandau Citadel in Berlin—on a new poison with “astounding properties.” His descriptions of the colorless, nearly odorless chemical that could kill victims in just 20 minutes sounded like it might be too good to be true. Although the soldier’s interrogators believed the story, British intelligence officers back in England did not. The 10-page report filed by the interrogators was ignored.

In the last months of the war, Hitler became increasingly apocalyptic, saying to his second-in-command, Albert Speer: “If the war is lost, the nation shall also perish.” In March 1945, Hitler issued a scorched-earth policy, called the Demolitions on Reich Territory Decree, commanding the destruction of German infrastructure to prevent it from falling into the hands of advancing Allies. Fearing for the country’s postwar future, Speer disobeyed parts of the directive.

In a subsequent postwar memoir and elsewhere, Speer made self-serving claims that he considered assassinating the Führer with tabun or one of the chemical weapons used in WWI. Speer said he began searching for a way to deploy the poison into Hitler’s underground Berlin bunker, where the dictator spent a majority of his time. Before the assassination attempt could be enacted, however, Speer claims Hitler ordered increased security around the bunker and blocked the bunker’s air vent with a 3-meter-high chimney because the dictator feared the approaching Russian Red Army might try to poison the bunker’s air.

Many find Speer’s story unconvincing: Skeptics think it absurd that one of the most powerful men in the Reich couldn’t find a ladder high enough to overcome the air vent’s chimney. Furthermore, after WWII, many former Nazis told blatant lies about their past to improve their image, legitimize their actions, and avoid prosecution. For example, Speer long claimed he knew nothing of the Holocaust, but documents discovered after his death reveal he was aware of what was happening at the Auschwitz concentration camp.

In early 1945, as the Allies continued to gain ground on German territory, the German Army went to extremes to hide their tabun- and sarin-filled munitions, “which are presumably not known to the enemy, [and] must under no circumstances fall into his hands,” noted a directive from German Field Marshal Wilhelm Keitel. But transporting these munitions to more secure areas was a challenge, in part because many railroad tracks had been bombed and the country was under frequent Allied air strike. In one catastrophic event, U.S. fighter pilots—unaware of the secret chemical cargo—dropped bombs on freight cars loaded with tabun-filled munitions near Lossa, Germany: Four of the town’s residents died from the fumes in minutes. In the end, thousands of tabun-filled bombs were transported for safekeeping primarily by barge, along rivers such as the Danube and Elbe.

As the Red Army approached the tabun factory at Dyhernfurth, the German military marched thousands of forced laborers off the compounds with little protection from the winter temperatures. Many who survived the exposure were murdered by the German secret police to prevent anyone who had participated in nerve gas production from spreading secrets. Still, the Russians discovered the tabun and sarin production plants, and once they found out about the new nerve agents, they disassembled the factory and reassembled it in Stalingrad.

American soldiers first encountered the secret chemical weapons when they shelled a barge traveling down the Danube River in Bavaria: To the American soldiers’ surprise, after just a few rounds of fire, the Germans waved surrender flags and admitted that the cargo—tabun-filled bombs—could kill them all. Meanwhile, the British Army discovered a bounty of files about the Spandau Citadel’s chemical weapons research hidden at Raubkammer, the initial testing site for tabun. As Allied scientists discovered that some German munitions contained a potent, unknown organophosphorus nerve agent that was much more toxic than anything they had in their own weapons inventory, they began to scramble to get their hands on the military spoils. Soon the Americans and British pooled resources and began searching for and rounding up scientists involved in chemical weapons research: When they arrested tabun inventor Schrader at his home, he immediately handed over chemical formulas and other details of the nerve agents. When American and British intelligence discovered that the Russians had rebuilt Dyhernfurth’s tabun and sarin plants in Soviet territory, there was no doubt a chemical arms race was under way.

As tensions rose between the U.S. and the Soviet Union, both burgeoning superpowers recruited German military scientists to their respective lands to capitalize on the Third Reich’s technological innovations. In the U.S., a paperclip was affixed to the file of any scientist who seemed desirable as a recruit. Then-president Harry Truman didn’t want militant Nazis brought to America, but many of the most promising scientists had been Nazi Party members. As a result, U.S. Army recruiters whitewashed the files to remove Nazi affiliations, wrote new biographies for the scientists, and issued them military security clearance and tickets to America.

The most famous beneficiary of Operation Paperclip was Wernher von Braun, who headed Nazi missile research, was a Nazi Party member, and then went to work for the U.S. National Aeronautics & Space Administration after the war. His expertise is widely cited as one reason U.S. astronauts were the first to reach the moon. Dozens of chemists were also recruited to work on chemical weapons at Edgewood Arsenal in Maryland and on synthetic fuels with the U.S. Bureau of Mines. The British Army had a similar program called Operation Matchbox. Working with other scientists, these former enemy chemists went on to help design, militarize, and stockpile next-generation nerve agents until the Chemical Weapons Convention entered into force five decades later, in 1997. 

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