A traveler heading northward from El Paso eventually enters a stretch of New Mexico desert so remote and hostile that the Spanish conquistadors dubbed it Jornada del Muerto — a phrase not easily translated. A jornada is a day of hard labor. Muerto means dead man. The dead man’s toil, perhaps. Or maybe: a long day’s journey toward death.

In the depths of that empty land, in the early darkness of a midsummer Monday in 1945, some 425 people, including some of the world’s most brilliant scientists and engineers, prepared to detonate the first nuclear explosive device. They called it “the Gadget.” Though the scene was only faintly illuminated by predawn light, they donned goggles as dark as welder’s shields. At 5:29 a.m., a flash erupted so intensely bright that it briefly blinded even through the lenses. One of the scientists, J. Robert Oppenheimer, thought of the Hindu scriptures that had inspired him since youth: “If the radiance of a thousand suns were to burst at once into the sky, that would be like the splendor of the mighty one.” Oppenheimer felt the weight of the purpose to which this awesome power — roughly equivalent to 44 million pounds of TNT, plus lethal radioactivity — would be put, and another line from the Bhagavad-Gita sprang to mind. “I am become Death, the destroyer of worlds.”

Three weeks later, on Aug. 6, a device of somewhat different design but operating on the same now-proven principles fell from the opened bomb-bay doors of a B-29 aircraft as the plane passed, propellers droning, over Hiroshima, Japan. Three days after that, Aug. 9, a third bomb, essentially identical to the Gadget, was dropped on the port city of Nagasaki.

Hiroshima after the atomic bombing. (U.S. Air Force)

Bodies of people who were thrown from a tramcar when the atomic bomb was dropped on Nagasaki. (Reuters)

Bombing victims sit in a damaged bank building converted into a hospital in Hiroshima on Oct. 6, 1945. (AP)

TOP: Hiroshima after the atomic bombing. (U.S. Air Force) BOTTOM LEFT: Bodies of people who were thrown from a tramcar when the atomic bomb was dropped on Nagasaki. (Reuters) BOTTOM RIGHT: Bombing victims sit in a damaged bank building converted into a hospital in Hiroshima on Oct. 6, 1945. (AP)

We have lived in the shadow of the Bomb ever since — 75 years, much longer than many people expected. At the news of Hiroshima, the St. Louis Post-Dispatch feared the event had “signed the mammalian world’s death warrant, and deeded an earth in ruins to the ants.” I shivered in that shadow as a boy growing up in a bull’s eye of the Cold War, and often doubted that I would live out a lifetime. Now that I nearly have, my fear has changed. I worry that the United States has come to take survival for granted.

Journalists announce and discard eras as casually as bingo numbers, but a true historical dividing line was blasted into the sands of New Mexico. Before the blinding flash, only gods destroyed worlds. Then the power passed into human hands. That dividing line is so stark that it obscures the long path that led to our nuclear fate. The Bomb is often presented as a discrete choice, an option unmoored from history, unrelated to the countless choices and decisions, accidents and discoveries, that produced it. A simple yes or no: Should Harry S. Truman, the new president of the United States in the summer of 1945, have allowed the use of those weapons? Could the surrender of Japan have been secured by less apocalyptic means, and at what cost? How many lives were destroyed? How many were saved? Such questions have been asked and argued over for 75 years — and will continue to be.

However, the Bomb is better understood as the terrible yet logical — and probably inevitable — result of a chain of developments in science, technology and the nature of war going back centuries. As if running on rails with unstoppable momentum, these developments moved in one direction only, toward ever more fearsome weapons and ever more catastrophic wars. This momentum made the nuclear age unavoidable.

Henry Stimson, the elderly secretary of war — a man of careful statements after many years of public service — alluded to this inevitability in April 1945. His memo to Truman brought the new president into the tight circle of secrecy around the development of “the most terrible weapon ever known in human history,” as Stimson put it. The Allies were given no choice but to outrace the Germans and Japanese and Soviets to this weapon, for its scientific basis was known to physicists around the world from the earliest days of the war. Unfortunately, the world’s “moral advancement” had not accelerated to keep pace with its technical proficiency, Stimson added ruefully, thus: “modern civilization might be completely destroyed.”

In the 75 years since, the famous Doomsday Clock of the Bulletin of the Atomic Scientists has never permitted much reason for hope: Its hands have always pointed to the final minutes before midnight. Yet the worst-case scenario remains in abeyance. What’s more, while the Bomb has not ended all wars, its menacing umbrella has spared the world from another industrial-scale conflagration among great powers. This is no small thing. During the last 31 years before the nuclear age, warfare consumed more than 100 million lives, the majority of them civilians. The only thing worse than Hiroshima and Nagasaki was the unspeakable brutality that preceded them.

In the New Mexico desert, perhaps — perhaps — the world finally found a weapon awful enough to end the escalation.

Understanding the Bomb in this context has never been more important, for the deadly momentum of war appears to be gathering again. Science and technology are revealing new ways to bring great powers into direct conflict: robotic and hypersonic weapons, space-based satellite killers, laser guns, cyberweapons. At the same time, the Bomb is proliferating. North Korea, an impoverished thugocracy, has the Bomb. Irreconcilable enemies India and Pakistan have the Bomb. Iran, a failing theocracy, has the infrastructure to build a Bomb. At what point does the unthinkable become unavoidable? The uneven ascent of China, the slow-motion meltdown of Russia, the mad belligerence of North Korea, the dangerous bluster of an incendiary U.S. president, the nihilistic dream of well-funded terrorists: Any catalogue of destabilizing forces is daunting. The nuclear umbrella is as tenuous as it is terrible.

Nuclear weapons offend some of humanity’s most widely shared principles. For some 2,500 years, since Thucydides and Aristotle — and likely much longer — great thinkers have tried to draw boundaries around the horrors of war, repeatedly carving a deep distinction between killing soldiers and killing civilians. The Bomb obliterates this distinction. It kills everything, leaving only — in the words of author Jonathan Schell — a republic of insects and grass. Indeed, to stop worrying and learn to love the Bomb, as filmmaker Stanley Kubrick put in his satiric masterpiece “Dr. Strangelove,” would be madness.

Yet the Bomb can’t be wished away or hated into nonexistence. It resists philosophy in favor of cold, illusionless facts. Principled, limited warfare has always been more wish than reality. Bright lines between military and civilian targets don’t survive the brute demands of combat. How does an army eat? Civilians grow the crops — and farms become targets. How does the army fight? Civilians make weapons — and die when their factories are bombed. Where are tomorrow’s soldiers found? Among today’s children — who are massacred. How do governments raise armies and send them into battle? Only with public support, which lasts until enough slaughter breaks the public will. Civilians live and work at the strategic choke points of war: the key towns, harbors, fields and junctions. Civilian and military targets are inseparable, and always have been.

The taking of cities is as old as Joshua at the walls of Jericho. To lay siege is to starve and torment indiscriminately. History is full of armies burning fields on which civilians rely, plowing farmlands with salt, fouling wells that supply water to soldier and civilian alike. Credible histories report that Genghis Khan, the great Mongol general, commanded the extermination of more than 1 million Persians in early 1221. Human warfare, wrote Robert D. Richardson, contains a blood-drenched register of “unremembered holocausts of appalling proportions.”

War rolls remorselessly past all referees. Of all human follies, perhaps the greatest is to think that war can be managed.

War also seeks an edge. Sometimes the advantage is high ground. Sometimes it is high tech. Around the year 1300, some clever engineer perceived the killing power of a longer bow firing heavier arrows. Result: Young King Henry V of England defeated a much larger French army at the Battle of Agincourt. In reply to the longbow: better armor. Muskets replaced the bows. Swift cavalry charges neutralized slow muskets. Long-range rifles blunted the cavalry. Trenches disarmed rifles. And so on. Did war drive technology, or did technology drive war? Yes, and yes.

With the industrialization of war, “better” technology often meant tools for killing large numbers from a relatively safe distance: heavy artillery, machine guns, poison gas, aerial bombs. Such weapons exacerbated the wantonness of war by relieving its bloody intimacy. A soldier with a bayonet fighting hand-to-hand knows exactly who lives and who dies. A pilot high above a targeted city knows only his briefing book. He drops his bombs on an arsenal and might never know if they land on an orphanage instead. Perhaps his payload includes incendiary bombs, seeding fires far below; perchance a wind whips up a firestorm.

A 1938 article in Scientific American examined the practice of bombing from the skies in the wake of the Japanese demolition of Shanghai, and the Italian and German attack on Barcelona, and offered this accurate forecast: “Although the outcome of the airplane offensive by means of aerial bombings remains an unknown, indeterminate quantity, the world may be sure that the unwholesome atrocities that are happening today are but curtain raisers on insane dramas to come.” The Nazi Luftwaffe built whistles into Stuka bombers to make them shriek as they attacked, and played a hideous overture with these instruments over Warsaw in 1939.

Then the curtain went up at Coventry, in England, when German bombs destroyed the city in a single night, Nov. 14-15, 1940. Many insane dramas followed, culminating on March 9, 1945, with the most destructive aerial attack of World War II — more deadly than either of the atomic blasts over Japan. The U.S. Army Air Corps’ Operation Meetinghouse, as the firebombing of Tokyo was called, left more than 100,000 people dead and 1 million homeless. All in one night.

Coventry Cathedral in the wake of an air raid in 1940. (Universal History Archive/Getty Images)

In a photograph known as “Bloody Saturday,” a crying child sits in the bombed-out ruins of Shanghai South Railway Station after a Japanese air attack in 1937. (H.S. Wong/Getty Images)

Tokyo shows the results of constant and heavy bombing raids by American B-29 Superfortresses during World War II. (Library of Congress)

TOP: Coventry Cathedral in the wake of an air raid in 1940. (Universal History Archive/Getty Images) BOTTOM LEFT: In a photograph known as “Bloody Saturday,” a crying child sits in the bombed-out ruins of Shanghai South Railway Station after a Japanese air attack in 1937. (H.S. Wong/Getty Images) BOTTOM RIGHT: Tokyo shows the results of constant and heavy bombing raids by American B-29 Superfortresses during World War II. (Library of Congress)

Enter science. The biography of the Bomb is told in one of the great nonfiction books of the 20th century, “The Making of the Atomic Bombby Richard Rhodes. The author juxtaposes the rise of nuclear physics as a thrilling scientific enterprise with the descent of human society into the depravity of modern warfare. Geniuses toggle back and forth between making dazzling discoveries and fleeing for their lives. At one point, the Danish theoretician Niels Bohr and his colleague George de Hevesy manage to dissolve the gold Nobel Prize medals of two colleagues, given to Bohr for safe-keeping, in acid to prevent them from falling into the hands of Nazis. If Hitler should be defeated, they knew they could reverse the chemistry, distill the gold from the acid, and ask that the medals be recast. Not long after, Bohr himself fled Copenhagen with only the possessions he could carry.

If Hitler should be defeated … but that outcome was very much in doubt when, in the first days of 1939, news tore through the scientific world that German chemist Otto Hahn and his colleague Lise Meitner had split uranium nuclei and successfully recorded a resulting burst of energy — a process Meitner and her nephew Otto Frisch dubbed “nuclear fission.”

The breakthrough was both thrilling and foreboding, for the previous decades had seen the greatest revolution in human understanding of physical forces since Isaac Newton. Leading that revolution was Albert Einstein, who early in the 20th century elaborated his theories of relativity and proved them by explaining mysteries of the night sky. One insight, especially fateful, was that energy and mass are the same thing in different forms. Further, the amount of energy (E) contained in any mass (m) could be found using a constant (c): the speed of light — squared. The speed of light times itself is a fantastically large number. Einstein’s equation, E=mc², awakened the world’s physicists to the stupendous energy bound up in the atomic structure of matter.

Scientists with immortal names like Ernest Rutherford, Max Planck, Bohr, James Chadwick, Enrico Fermi, Leo Szilard, Ernest Lawrence, Edward Teller and Oppenheimer probed ever more deeply into the atom and its subatomic particles. As they dug, Einstein’s latent energy was never far from their minds. Yet they weren’t trying to kill anyone. They wanted to understand the building blocks of existence.

At the same time, however, these scientists had lived through the so-called Great War, perhaps the most disillusioning event in human history, begun for no good reason and ended, after some 20 million dead, with nothing gained. World War I gave the world the barbarity of poison gas attacks, the monstrous advent of tank cavalry and the introduction of aerial bombing of civilian targets. So they could all foresee where the fission breakthrough might lead. If particles of a splitting atom could sail off to split more atoms, and so on in a chain reaction, the energy released could be extraordinary. The momentum of war meant that what could be done would be done. The only question was, by whom?

Alerted by a letter from Einstein and egged on by rapid scientific progress, President Franklin D. Roosevelt bent the full weight of the United States toward being first to build the Bomb. Known in the Pentagon as S-1 and elsewhere as the Manhattan Project, the effort consumed 5½ years and the labor of more than 600,000 workers to arrive on Truman’s desk as a fait accompli.

Truman will forever be second-guessed, as anyone taking so momentous a step ought to be. As the Bomb became a reality, the first hints of an emerging peace faction within the Japanese government reached Washington. But the upper hand in the Empire still belonged to a cult of death inside the military — personified by the kamikaze but running all the way to the top. How credible was the talk of Japanese surrender? The firebombing of Tokyo had produced little apparent weakening in Japan’s resolve. As Army Chief of Staff George C. Marshall recalled: “We had had one hundred thousand people killed in Tokyo in one night of bombs, and it had seemingly no effect whatsoever.” If anything, Japan’s resistance seemed to stiffen: After Tokyo, on the island of Okinawa, Japan waged a suicidal defense that drenched Truman’s first months as president in blood.

When I was in grade school, my older brother and I shared a window between our twin beds, and for several years it showed nothing but the wide horizon. Around 1970, several enormous snow-white geodesic domes appeared in the frame about five miles away. They landed on the high prairie east of Denver as if lobbed there by gods. Everyone called them the golf balls.

They were mysteries at first. As we gathered fragments of overheard information about them, their presence became exciting, and then dangerous. They placed us on the front lines of the Cold War. While the world was watching astronauts close in on the moon, the United States was also busy in another corner of space, deploying a network of spy satellites to monitor the globe for missile launches. The thin, dry atmosphere of our semiarid plateau was good for something other than tumbleweeds and cracked lips. It was ideal for communicating with satellites.

Even children could put the pieces together from there. The golf balls were the eyes of the United States’ nuclear defense, which meant that we lived on the eyelashes. We didn’t know the term “collateral damage,” but we grasped the concept. Somewhere halfway around the world, hydrogen bombs were targeted for the obliteration of those golf balls — multiple bombs, perhaps, just to be sure — each one vastly more powerful than the atomic bombs dropped on Japan.

I used to stare through that window and imagine a blinding flash of a million suns: the last sensation before all that I knew and everything I cared for — starting with my own gawky, dreaming, yearning self — would disappear in a hurricane of fire. I took a little pride in knowing that my world mattered enough to be destroyed in the first moments of Armageddon.

Mostly, though, I was afraid.

But we’re still here — me, the golf balls, the rest of humankind — half a century later. What strikes me now is that, though we worried about nukes, my friends and I played endlessly as conventional soldiers. Running across front lawns, we fired imaginary rifles at one another and pulled the pins on hand grenades to wipe out machine-gun nests as we dove for cover. Soaring on the playground swings, we fought off German Messerschmitts and dumped our bombs on Berlin. I wonder: Could we have made a game out of the worst catastrophe in history, World War II — an event only 25 years distant at that time — if the Bomb had not rendered another such war obsolete?

The nuclear age finally cured the insanity of industrial war by replacing it with another brand of madness, predicated on mutually assured destruction. The doomsday devices that keep our fragile peace have put the brakes on the momentum of escalating violence, but we’re stuck with them, hideous guard dogs. They are the best we could do. The killing racheted up until the only remaining step was apocalypse.

It’s commonplace today to hear political and thought leaders from every point of the spectrum, from nations around the world, wish that nuclear weapons had never existed and call for their elimination. Don’t they know what the world was like before the Bomb? They speak as if these weapons “brought Death into the world, and all our Woe,” to borrow from Milton. But death and woe were thriving long before the Bomb arrived.

From the peak of the Cold War, the world has steadily trimmed its nuclear stockpiles. Today, the United States and Russia have roughly equal numbers of nuclear bombs — around 6,000 each, a nightmarish number. But these two nations have owned 90 percent of the world’s total nukes for many years without using them, and they have plans to dismantle thousands more. The question is: How low should we go?

The Ohio-class ballistic-missile submarine USS Wyoming approaches Naval Submarine Base Kings Bay, Ga., in 2008. (Lt. Rebecca Rebarich/U.S. Navy via AP)

A vehicle transports a RS-24 Yars strategic nuclear missile along a street during a Victory Day rehearsal in Moscow on June 17. Russian President Vladimir Putin postponed the traditional May 9 parade because of the coronavirus. (Andrey Rudakov/Bloomberg)

People watch a TV showing a file image of a North Korean missile launch during a news program at the Seoul Railway Station on July 25, 2019. (Ahn Young-Joon/AP)

TOP: The Ohio-class ballistic-missile submarine USS Wyoming approaches Naval Submarine Base Kings Bay, Ga., in 2008. (Lt. Rebecca Rebarich/U.S. Navy via AP) BOTTOM LEFT: A vehicle transports a RS-24 Yars strategic nuclear missile along a street during a Victory Day rehearsal in Moscow on June 17. Russian President Vladimir Putin postponed the traditional May 9 parade because of the coronavirus. (Andrey Rudakov/Bloomberg) BOTTOM RIGHT: People watch a TV showing a file image of a North Korean missile launch during a news program at the Seoul Railway Station on July 25, 2019. (Ahn Young-Joon/AP)

Instead of aiming toward zero, the world should devote its energies to strengthening the global framework that allows us to live with our fearsome peacekeeper. For the United States, this begins at home. The world’s most powerful nation must resume its responsibilities as custodian of the nuclear peace. Though America’s arsenal is roughly equivalent in numbers to the Russian stockpile, it is massively more threatening, more decisive, because of the unstoppable nature of our nuclear submarine fleet — virtually impossible to detect, and able to launch its missiles from underwater. Allies and rivals alike need to know what the United States will defend, what it will allow and what it will deter. If the world can’t trust the United States, with its overwhelming nuclear advantage, to stand guard and enforce a degree of peace, other nations will feel obligated, or emboldened, to create their own nuclear umbrellas.

Second: The world needs to enforce nonproliferation, rewarding nations that give up their nuclear ambitions and punishing those that pursue the Bomb. This may seem obvious, yet it requires an about-face after a disastrous decade. Libya’s Moammar Gaddafi voluntarily gave up his pursuit of nuclear weapons. His reward was a humiliating death and the dismemberment of his country. Kim Jong Un of North Korea defied the world and received a profession of “love” from President Trump. Everything about our current path is wrong.

Third, nuclear testing bans must be updated, reaffirmed and renewed. The 1996 Comprehensive Nuclear-Test-Ban Treaty has never been ratified by the United States, and members of the Trump administration have proposed new low-level tests. They offer as justification China’s lack of transparency concerning activity at its principal nuclear arms facility. In Russia, meanwhile, a mysterious accident related to a missile test released significant radiation, according to Russian public health officials. Here, too, we need an about-face. The United States should endeavor to bring China into the test-ban negotiations as a full partner, either to conclude the existing treaty after all these years or to negotiate a new and better one. Nothing learned from new tests could outweigh the danger that rogue nations will use them as excuses to arm themselves.

Fourth, the United States should launch a new generation of arms-control negotiations, focused on competition in space and cyberspace. The battlefields of future great-power conflicts are likely to be very different from the mud and blood of past wars. And yet, one nation’s attack on another nation’s spy satellites, or a massive preemptive cyberattack on another nation’s electrical grid, would be just as provocative as a column of tanks rolling across a border. America can negotiate from a position of strength in space, but we can’t afford to let war in a new dimension drag the world back to the nuclear brink.

All of these urgent steps require a new blast of the sort of statesmanship that characterized postwar American leadership. Truman and his administration fostered the creation of the United Nations, the World Bank, the International Monetary Fund, NATO and other institutions to lend stability to a world that had become too dangerous to leave to itself. The success of American-led internationalism has become its own worst enemy. People have come to take stability for granted.

It’s exhausting — and depressing — to think of another 75 years under the shadow of the Bomb … and another 75 after that … and so on until technology (or an unforeseen forward leap in the moral tenor of human nature) delivers a safer way to deter the tendency to total war. We wish to be freed from anxiety and fear, to leave the Jornada del Muerto behind us forever. I wished that wish in my boyhood bedroom. I wish it today.

It shall not be granted, alas. For there are far worse tortures than anxiety and exhaustion, and humans have proved ourselves more than capable of inflicting them on a wanton scale. We tortured and killed until it seemed there was no limit on what we would do to one another. The destroyer of worlds finally drew the line.

Read more:

George F. Will: One of humanity’s remarkable achievements is the absence of the use of a third nuclear weapon

The U.S. hid Hiroshima’s human suffering. Then John Hersey went to Japan.

In the 75 years since Hiroshima, nuclear testing killed untold thousands

Max Boot: Trump’s nuclear brinkmanship keeps backfiring, but he keeps doubling down

Victoria Nuland: What Ronald Reagan would tell President Trump about arms control

Barack Obama: How we can make our vision of a world without nuclear weapons a reality