Latest / The History of Germany: Kingdoms, War, and Rebuilding Europe — Fexingo History / Germany's Poison Gas: The First WMD and the Scientist Who Fought It
Transcript
- Lucas: So far in this series, we've seen Germany become a military titan under Bismarck, then a nervous empire under Wilhelm II, and then plunge into the catastrophe of the First World War. But there's one weapon that Germany unleashed in that war that changed everything—poison gas. And the man most responsible for it has one of the most complicated legacies in all of science. Luna: I've heard of Fritz Haber. He's the guy who invented the Haber-Bosch process, right? Lucas: Exactly. The Haber-Bosch process—named for Haber and the engineer Carl Bosch—synthesizes ammonia from nitrogen and hydrogen. It's arguably the most consequential chemical process of the 20th century. Without it, we couldn't produce enough fertilizer to feed billions of people. Haber won the Nobel Prize for it in 1918. Luna: But he also invented chemical warfare. Lucas: He didn't just invent it—he personally championed it, oversaw its deployment, and stood on the battlefield to see it work. When World War I broke out, Haber was a patriotic German Jew. He was 45, too old to fight, but he volunteered his scientific genius to the war effort. The German army had a problem: trench warfare was a stalemate. They needed a breakthrough. Haber proposed using poison gas. Lucas: Now, chemical weapons weren't entirely new. The French had used tear gas grenades earlier, but Haber wanted something lethal—chlorine gas. Chlorine is heavier than air, so it would sink into trenches. And it attacks the lungs, causing a slow, agonizing death by asphyxiation. The German High Command gave him the green light. Luna: That's horrifying. And this was in 1915? Lucas: April 22, 1915, near the Belgian town of Ypres. The Germans had installed over 5,000 cylinders of chlorine gas along their front line. At around 5 PM, they opened the valves. A grey-green cloud, about six feet high, drifted across no-man's-land toward French and Algerian trenches. The soldiers had no protection. They panicked, choked, and fled. The gas killed around 1,100 men and wounded thousands more. It created a four-mile gap in the Allied line. Luna: And the Germans didn't exploit it? Lucas: They weren't prepared for such a huge breach. They hadn't brought enough reserves. So the breakthrough stalled. But the psychological impact was massive. Chemical warfare had begun in earnest. Haber returned to Berlin a hero—but not everyone was impressed. Luna: His wife, Clara Immerwahr, was a chemist too, wasn't she? Lucas: Yes, Clara was the first woman to earn a PhD in physical chemistry in Germany. She was a pacifist and deeply opposed to Haber's work. The night he returned from Ypres, they had a terrible argument. She called his work 'a perversion of science.' Early the next morning, she took his service revolver and shot herself in the chest. She died in their garden. Their 12-year-old son found her. Luna: That's devastating. And Haber just... went back to work? Lucas: Essentially, yes. He left for the Eastern Front that same day to oversee another gas attack. He never spoke of her suicide publicly. But it cast a long shadow. Haber threw himself even more into the war effort. He developed a gas mask to protect German troops—and then new gases like phosgene and mustard gas. Mustard gas, first used by Germany in 1917, caused horrific blisters and blindness. It wasn't usually lethal, but it could take weeks to recover, tying up medical resources. Luna: So Germany essentially created the template for chemical warfare. Lucas: They did. And after the war, the Treaty of Versailles explicitly banned Germany from developing or using chemical weapons. But that's not the end of the story. Haber's institute, the Kaiser Wilhelm Institute for Physical Chemistry in Berlin, continued to pursue gas research. And one of his colleagues, Otto Hahn, would later win a Nobel for nuclear fission. Another, Walther Nernst, had already won one for thermodynamics. Luna: But Haber's legacy gets even darker, doesn't it? Lucas: Much darker. After the war, Haber's team developed a pesticide based on hydrogen cyanide called Zyklon B. It was used to fumigate ships and barracks against vermin. Later, under the Nazis, Zyklon B would be used in the gas chambers of Auschwitz. Haber himself was Jewish, so he fled Germany in 1934, after the Nazis came to power. He died in exile in Switzerland the same year, broken and isolated. Luna: So his invention—the Haber-Bosch process—feeds the world. But his other work kills on an industrial scale. How do you even reconcile that? Lucas: You can't, really. Haber himself once said, 'During peace time, a scientist belongs to the world; during war, to his country.' He saw his work as patriotic duty. But the question of moral responsibility haunts his legacy. Did he ever regret it? He told a colleague once that he was haunted by the faces of dying soldiers. But he also said he considered gas a humane weapon—because it could end wars faster. Luna: Humane? That's insane. Lucas: It's a rationalization, but it reflects the thinking of the time. Many chemists in Germany and elsewhere saw gas as a legitimate weapon. The Allies also developed and used chemical weapons. In fact, Winston Churchill supported using gas against rebellious tribes in Iraq in the 1920s. But Germany was the pioneer, and the stigma stuck. After World War I, the Geneva Protocol of 1925 banned chemical weapons, though it didn't stop them from being used later. Luna: What happened to Haber's institute after the Nazis took over? Lucas: The Kaiser Wilhelm Institute was renamed and continued research. Many of Haber's Jewish colleagues were dismissed. Some, like the physical chemist James Franck, left in protest. The institute eventually contributed to Nazi weapons programs, though not directly to the Holocaust. The Zyklon B used in Auschwitz was manufactured by a different company, Degesch, which Haber had once held shares in. Luna: So the same man who fed the world also indirectly enabled the gas chambers. Lucas: It's a tragic irony. Haber's story forces us to confront the dual-edged nature of scientific progress. The Haber-Bosch process is estimated to have sustained about half the world's population through fertilizer. Without it, billions would starve. But the same ingenuity used to fix nitrogen was used to kill. Haber is both a savior and a war criminal. And that ambiguity is the heart of his story. Luna: I wonder how he saw himself in the end. Did he ever show remorse? Lucas: In his final months, he wrote a letter to a friend saying he felt like a 'dead man'—his life's work had been perverted. But he never publicly apologized. He remained a German patriot who believed he had served his country. In 1933, when the Nazis dismissed him because of his Jewish ancestry, he was shattered. He said, 'I have served Germany all my life. What more can I do?' Luna: So he was a victim of the Nazis too, in a way. Lucas: He was, but that doesn't absolve him. His story is a cautionary tale about how the best and brightest can be seduced by nationalism, and how science can be twisted into a weapon. Germany's history is full of such moments—where technical brilliance meets moral catastrophe. Haber is the human face of that collision. Luna: I think I need to sit with this for a while. Thanks, Lucas. Lucas: Take your time. Next time, we'll look at a different kind of German weapon—one that didn't exist yet but was already being imagined: the V-2 rocket.