A hundred years ago this month, the First World War shuddered to a close. The end came when the armistice took effect on the Western Front at 11 am on November 11, 1918—the famous eleventh hour of the eleventh day of the eleventh month, a phrase that seems like an obscenity now, a romantic gesture to cap a war that long before should have buried any possible remaining romance of war. The armistice had been coming since at least August 8, 1918, the “black day of the German Army,” when some 15,000 German men surrendered on the first day of a French and British offensive. Germany’s allies had been dropping away since September, with Bulgaria, then the Turks, then Austria-Hungary suing for peace.

The Germans had initiated peace negotiations on November 8, and their delegates pleaded that fighting be suspended at once. Marshal Ferdinand Foch, the supreme Allied commander, refused. The signing of the armistice agreement was announced at 5:45 on the morning of November 11, but Foch decreed that the official ending time would be eleven o’clock.

In the ensuing five hours and fifteen minutes, the two sides suffered a combined 10,944 casualties, including 2,738 dead, according to the historian Joseph E. Persico in his book Eleventh Month, Eleventh Day, Eleventh Hour. The fighting went on, to get revenge, to use up “leftover” ammunition, to teach the enemy a lesson. It continued because, even after four years of what British prime minister David Lloyd George would call “the cruellest and most terrible war that has ever scourged mankind,” men were still willing to go dutifully forward to kill when they were ordered to do so.

Most of the killing that last morning seems to have been initiated by the Allies, but the Germans shelled the town of Mézières, flattening the hospital there, and ambushed British troops at a little village near Valenciennes. British cavalry raced into the Belgian town of Lessines at ten to eleven, where they chased down German defenders as if they were on a fox hunt.

“I fired 164 rounds at [the enemy] before he quit this morning,” Captain Harry S. Truman, the only future American president to see action in World War I, wrote. Truman, the commander of an artillery battery, maintained, “I’m for peace, but that gang should be given a bayonet peace and made to pay for what they’ve done to France.” He kept his guns flaring until precisely eleven. Some American artillery batteries kept banging away even past that deadline.

Colonel Thomas Gowenlock, an intelligence officer with the US 1st Division, was surprised to find the shelling from both sides unusually heavy and growing worse as he approached the front near Le Gros Faux. “It seemed to me that every battery in the world was trying to burn up its guns. At last eleven o’clock came—but the firing continued,” Gowenlock would write in his memoir of the war.

Numerous American units—the 32nd and 33rd Army divisions, the 5th Marine Regiment—were ordered into combat that morning and suffered serious losses. The all-black 366th Regiment of the Army’s 92nd Division, in America’s segregated armed forces, was ordered to make three separate assaults on German positions heavily fortified with machine guns; the last one commenced at ten-thirty, and the troops absorbed 319 casualties that day, including seventeen dead.

How did their commanders justify so many deaths to so little purpose? Mostly by lying about it. Persico, checking the eyewitness battlefield reports of dead and wounded against the subsequent official military histories, found numerous “discrepancies” driving down the numbers recorded in those last, futile hours. Even taking at face value the official counts, Persico concludes, had Foch and the Allies acceded to the German request for a ceasefire to commence with negotiations on November 8, likely, 6,750 lives would have been spared and nearly 15,000 maimed, crippled, burned, blinded, and otherwise injured men would instead have gone home whole. All this sacrifice was made over scraps of land that the Germans, under the armistice, were compelled to surrender within two weeks.

When the guns finally did stop, the reaction was muted. In some sectors, the former combatants embraced, drank wine together, shook hands. But elsewhere, remembered one British corporal, “the Germans came from their trenches, bowed to us, and then went away. That was it. There was nothing with which we could celebrate, except cookies.”

Colonel Gowenlock recorded that, in his sector,

many soldiers believed the Armistice only a temporary measure and that the war would go on. As night came, the quietness, unearthly in its penetration, began to eat into their souls. The men sat around log fires, the first they had ever had at the front. . . . They talked in low tones. They were nervous.

Gowenlock concluded, “Their minds were numbed by the shock of peace.”

Perhaps there was no other way a war that began with such a personalized act of violence could end. That was the assassination of Archduke Franz Ferdinand, heir to the throne of Austria-Hungary, by one Gavrilo Princip, a nineteen-year-old Serbian nationalist recruited by the Black Hand conspirators in Serbia’s intelligence service.

Princip, a slight, sunken-eyed, hollow-cheeked peasant’s son sporting a bad mustache, thought that he and his fellow conspirators had failed when a bomb one of them hurled at the archduke’s car went astray. He was standing outside a delicatessen along the parade route when the royal automobile suddenly reappeared, tried to back up, and stalled. Princip stepped forward and shot Franz Ferdinand in the neck, fatally wounding him. He then shot the archduke’s morganatic wife, Sophie, the duchess of Hohenberg—a minor noblewoman with absolutely no political standing.

At his trial, Princip wrapped up his crimes in patriotic motives: his desire to see the creation of a unified, all-Slav nation—a “Yugoslavia.” Because the Austro-Hungarian Empire in 1914 did not execute anyone under the age of twenty, he was sentenced to life in prison. Suffering from skeletal tuberculosis, the spindly Princip slowly wasted away in confinement, finally dying in the spring of 1918. Left behind on the wall of his cell was a vow on behalf of himself and his fellow conspirators: “Our ghosts will walk the streets of Vienna / And roam through the palace / Frightening the Lords.”

Yet most of the lords escaped in the end, as lords will. Not so much the ordinary people, who would die in the tens of millions thanks to the wars that Princip touched off. No nation lost nearly as large a percentage of its population in the First World War as the Serbia that propelled Princip on his way, with somewhere between 750,000 and 1.25 million total deaths, or between 17 and 28 percent of its population. Mankind would be introduced to the Shoah of European Jews and the Armenian holocaust; the massacre of the Romani; the rape of Nanking; the Bengal famine of 1943; and Hiroshima and Nagasaki. We would need a whole new word—“genocide”—added to our vocabulary for all the carnage that was to come.

Princip would get his Yugoslavia, all right, though he wouldn’t live to see it. The nation of “All Slavs” lasted less than seventy-five years, nearly all of them spent under the thumb of dictatorship or in bloody, internecine war, before it dissolved in one final spasm of genocide. Princip became an enduring Serbian hero, though, with plaques and museums and statues, streets and babies, named in his honor, and maybe that would have made it worthwhile for him, this young man who preferred to think of other people as political abstractions even as they sat before the barrel of his gun. His own slow death never led him to express any regret over the carnage he had unleashed, only anxiety that Yugoslavia might not come into being.

It is not hard to draw a straight line from Gavrilo Princip to, say, Dylann Roof, slaughtering the black women and men of Charleston, South Carolina, who had let him into their prayer meeting, because some modern, internet equivalent of the Black Hand had told him it was for the greater ethnic good. To Lenin, avenging the hanging of his brother on the tsar, the tsar’s children, and all of Russia; to Osama bin Laden, whose father died in a plane crash, crashing planes into buildings; to Oswald and Sirhan and James Earl Ray and Mark David Chapman—those unhappy children to whom evil was done and who did evil in return. To how many countless other men who can’t get a job, can’t get a wife, can’t get laid, can’t still those voices in their heads. Are dissed by the boss, dread their feelings for other men, want purity, want to be known, want to be respected, want to matter. We have lived in the century of the man with a gun, always set to avenge whatever wrongs, real or imagined, were done to him. These men weaponize what they can, for the greater or lesser evil—maybe an army, maybe a creed, maybe a whole people—or just grab the first gun they can find and head off to that meet and greet for the candidate, that country music concert, that gay nightclub down the block, that Christmas party for their fellow employees. They are the leitmotif of our time, and if they do not draw their inspiration directly from Gavrilo Princip, he and a dozen others are always there in the pantheon of these past hundred years—a permanent memorial to how much violence does indeed accomplish.

Princip managed to tip a West that believed, with considerable justification, that it was becoming steadily more civilized and less violent back into its fully savage past, complete with more murderous toys. This reversal was a profound psychological shock, one that Europeans and Americans wondered over even as it occurred.

Of course, the old barbarisms had always been kept alive offshore, with genocide regularly practiced but rarely admitted—in German West Africa and the Belgian Congo, British-administered India, and the Philippines under US control. It is entirely possible that a Europe not badly weakened by the world wars it instigated would have been all the more unwilling to give up its colonial empires, thereby turning this century into an even bloodier war of white against all, of which so many racial supremacists of the Atlantic world dreamed.

But another casualty of the First World War were those gentle social democrats who were at the time the most inclined to believe in the common humanity of all mankind. They were run over as their nations rushed to war, murdered or jailed, and not by happenstance: Jean Jaurès, the great French Socialist leader, shot dead by a nationalist in 1914 as he struggled against the slide into war; an American Socialist Party that had won 6 percent of the presidential vote in 1912 and elected 1,200 candidates to office, utterly crushed during the wartime Red Scare, its beloved sixty-three-year-old leader, Eugene V. Debs, sentenced to ten years in federal prison for daring to obliquely criticize the draft; Rosa Luxemburg, the diamond-hard jewel of German socialism, beaten and shot by storm troopers who tossed her body into a Berlin canal.

The effort to imbue the war, ex post facto, with greater meaning at the Versailles Peace Conference—namely, that it might mark the end of all wars—was also a failure. Almost everything we were taught in school about Versailles is a myth. Saintly President Wilson, betrayed by France and En­gland, whose unquenchable desire for revenge doomed the Germans’ efforts to make democracy work. Wilson was doomed mostly by his own obdurate nature, exacerbated by a series of strokes. Contrary to what John Maynard Keynes wrote in The Economic Consequences of the Peace, the reparations imposed on Germany were not particularly onerous, not nearly as onerous as those Germany had imposed on France in 1871 or the demands it had imposed on every country it occupied or defeated earlier in World War I—and in any case, Germany never paid most of them, at least not until after the next war. The hyperinflation in 1922 and 1923, with its notorious wheelbarrows full of cash needed to buy a loaf of bread, ended nearly ten years before Hitler came to power, and, as Liaquat Ahamed argues in Lords of Finance, the inflation was largely a self-inflicted condition, thanks to German resentments and mismanagement. Once freed from the cost of paying any reparations, Germany promptly embarked on a much more expensive program of rearmament.

The real ghosts of Versailles are all around us. It proved to be a “peace to end all peace,” as David Fromkin called it in his history by the same name. A hundred years later, we are still trying to deal with the breakup of the Ottoman Empire, which gave us the modern Middle East, the end of the Romanov dynasty, which eventually bequeathed us Putin’s Russia, or even the dissolution of that frothy Viennese hodgepodge, the Austro-Hungarian Empire.

Margaret ­MacMillan suggests, in Paris 1919, the most perceptive history of the peace, that any better resolution than what we got was probably impossible in the first place. Woodrow Wilson’s proposal to build ethnic states out of the wreckage of the collapsed empires may have reflected a constant demand, but it was hardly feasible. There were, it turned out, Germans in the All-Slav state, Germans in the new Czechoslovakia, Germans in Poland, Germans and other national minorities everywhere. They would be of invaluable propaganda value to Hitler and lesser demagogues, as would the demanded reparations, and the infamous Article 231 of the Versailles Treaty, which laid all guilt for World War I at the feet of Germany. This last was certainly unfair, but would a Germany unblamed and unshamed after 1918, the power of its military Junkers undiminished, have made a congenial partner for peace in the center of Europe? And how could such a state of affairs have been justified after all the sacrifices of the war, and all the depredations perpetrated by Germany throughout its duration?

“The peacemakers,” ­MacMillan concludes, “had to deal with reality, not what might have been,” and to blame them for all that came after “is to ignore the actions of everyone—political leaders, diplomats, soldiers, ordinary voters—for twenty years between 1919 and 1939.”

The same critique might be extended to the present day. Outside of Europe, as ­MacMillan also notes, the peacemakers simply “carried on the old practice of handing out territory to suit the imperialist powers” or “threw together peoples,” regardless of their histories and cultures, in new colonies and “protectorates.” Today, the refugees staggering out of these failed states provide new scapegoats for new demagogues.

We remain, it seems, speaking in low, nervous tones around the fires in our trenches, our minds still numbed to the idea of peace.