German Red Cross workers carry bottles of liquid to help revive those who had succumbed to a gas attack during World War I. (Associated Press)

Dan Zak is a reporter for The Washington Post and author of “Almighty: Courage, Resistance and Existential Peril in the Nuclear Age.”

Here is a book that will burn your nostrils and make your throat close. Its main characters are asphyxiants and vesicants — mustard gas, chlorine and other chemicals deployed in World War I — and author Theo Emery describes in vivid, bronchial language how they sowed agony through the fields and forests of Europe, and how they afflicted soldiers, scientists and innocent bystanders on the home front. Another kind of agent is at play here, too, and it's as insidious as any poison fog: the bureaucracy that ensured that the United States, late to the war, throttled its way to chemical supremacy, damn the cost, risk and moral peril. Emery's "Hellfire Boys: The Birth of the U.S. Chemical Warfare Service and the Race for the World's Deadliest Weapons" may lack suspense, but it brims with shock and surprise.

A century has passed since the United States entered the Great War — the last surviving veteran died in 2012 — and there has been enough ensuing horror on the battlefield to bury its particulars in the collective memory. The atomic bomb, a generation later, multiplied the horror of combat by a million. Vietnam became shorthand for military folly scented with napalm and Agent Orange. Over the past few years, the regime of Bashar al-Assad has practiced the dark sorcery of sarin gas and chlorine barrel bombs, which were “the original chemical weapon of the twentieth century,” as Emery calls it, first used in 1915 in Belgium.

Though squarely a crackling history, “Hellfire Boys” is also a relevant primer on the past 100 years and on a kind of total warmaking that continues to haunt us — sometimes from another hemisphere, sometimes in our own back yard.

“Hellfire Boys,” by Theo Emery (Little, Brown and Company)

Emery’s introduction opens on Spring Valley, a leafy upper-class neighborhood abutting the campus of American University in Northwest Washington. There, in 1993, the U.S. military disinterred 144 pieces of World War I-era munitions, including unexploded mortar rounds: the remains of the government’s chemical effort to fight fire with fire against the Germans. With the university’s permission, the area had been used as a giant laboratory to make and test some of mankind’s nastiest concoctions.

“Hellfire Boys” is a story of collaboration, of public-private partnership, of a marriage between science and industry. Many corners of the country mobilized to aid the war effort. Twenty thousand pounds of phosgene, a choking gas, were produced daily in Niagara Falls, N.Y. In Gunpowder Neck on the Chesapeake Bay, shells were filled with chemicals before being shipped across the Atlantic. Lewisite, a blistering agent, was made in Willoughby, Ohio. Helium came from Texas, cyanide from Tennessee, mustard from Rhode Island, gas masks from Long Island.

This enterprise was possible only through the bureaucratization and industrialization of pain and death. “Hellfire Boys” shows how the United States, and the world, brought scientific sophistication and mechanical efficiency to the barbarism of war. Emery toggles among appropriators in the halls of Congress, chemists on noxious proving grounds, and shivering soldiers in Flanders Fields who had to fight with and defend against new and frightening weapons. The book overflows with characters, and Emery wisely provides a dramatis personae at the start of the book. Two individuals stick out: Harold “Higgie” Higginbottom, a 21-year-old chemist and early recruit to the First Gas Regiment, and Amos A. Fries, an engineer who became chief of the Army’s nascent gas forces and a cheerleader for chemical warfare.

These men, a grunt on the front lines and a savvy bureaucrat in the halls of power, embody the fascinating spectrum of this war effort, an undertold story in a nation more fluent in the heroics and horrors of World War II. Emery’s reporting is vast and meticulous, and his storytelling is focused and clean. He gathered a wealth of materials, including Higginbottom’s detail-rich diaries and letters, which put the reader in the muddy trenches as thousands of shells fly through the sky.

“When he reached the billet,” Emery writes, Higgie “was finally able to slow down and ponder what had happened in that moment of pure silence just before he pushed down the plunger on the detonator. When the projectors roared and sent six hundred pounds of gas at the Germans, he felt he was in the war at last.”

Back in Washington, Fries told Congress that chemical warfare “is the most humane” kind of combat but then lobbied on behalf of its ghastliness: “If we could make war so terrible that there would not be any chance for it to last more than five or ten minutes, then they would stop all wars.” Emery, in a rare but judicious editorial aside, notes the absurdity and “convoluted logic” of a man beholden to industry above humanity.

Chemists helped to make war terrrible in new ways, but these ways were not terrible enough to stop it. “Hellfire Boys” is the story of a Rubicon crossed, a Pandora’s box opened. The United States, goaded by its foes, flouted conscience and the conventions of war to ensure victory and achieve peace. This Faustian bargain, Emery writes, was prologue to the next world war; the U.S. Chemical Warfare Service was a dry run for the Manhattan Project 15 years later, when physicists took the baton on innovating weaponry. In a world where whole towns had already been poisoned by “the devil’s perfume,” the notion of incinerating a city seemed like just another scientific pursuit, just another do-or-die tactic for securing victory and achieving a more complicated and precarious peace.

Hellfire Boys

By Theo Emery

Little, Brown. 535 pp. $29