World War I

To understand the catastrophe, you first have to picture the world it destroyed. In the summer of 1914, Europe stood at what looked like the summit of civilization. Its cities blazed with electric light; its ocean liners crossed the Atlantic on schedule; its telegraph cables carried prices and news around the globe in minutes. Trade flowed freely, money moved on a shared gold standard, and educated people spoke confidently of progress as a law of nature. It was, in many ways, the first great age of globalization—and almost no one believed it could end in fire.

Indeed, a popular idea of the day held that a great war between the industrial powers had become impossible. In his 1910 bestseller The Great Illusion, the writer Norman Angell argued that the economies of Europe were now so tightly bound together that a major war would ruin victor and vanquished alike—and so, being irrational, would not be fought. Millions found the argument persuasive. They were about to be proven catastrophically wrong.

It was also a family affair. Kaiser Wilhelm II of Germany, Tsar Nicholas II of Russia, and King George V of Britain were all related—Wilhelm and George were first cousins, and both were tied by blood or marriage to Nicholas. They called one another "Willy," "Nicky," and "Georgie" in their letters. Yet kinship at the top counted for nothing against the machinery beneath them: a web of secret alliances and mobilization timetables that could turn a single spark into a continental blaze.

This is the story of how that confident world came apart. It ends, as all such stories must, with an attempt to make peace—the Treaty of Versailles of 1919—that instead planted the seeds of the next catastrophe. But it begins with the tensions that had been building for a generation, in a corner of Europe that diplomats had already learned to call "the powder keg."

No single cause explains the First World War. Historians have argued about it for more than a century, and they still do. But most agree that four deep forces had turned Europe into something combustible: militarism, alliances, imperialism, and nationalism. Each pressed on the others, and together they built a structure that only needed a match.

Militarism meant more than large armies. It meant societies that glorified military strength, general staffs that wielded enormous influence, and, crucially, war plans so rigid that once mobilization began it was almost impossible to stop. The most spectacular expression of it was the naval race between Britain and Germany. When Britain launched HMS Dreadnought in 1906—a battleship so advanced it made every other warship obsolete—Germany raced to build its own. The two nations poured fortunes into steel and guns, and each came to see the other's fleet as a dagger pointed at its heart.

Alliances divided the continent into two blocs that promised to defend one another. On one side stood the Triple Alliance of Germany, Austria-Hungary, and Italy; on the other, the Triple Entente linking France, Russia, and Britain. The system was meant to keep the peace through balance and deterrence. Its fatal flaw was that it could just as easily transmit a small conflict outward, like a chain of climbers roped together on a cliff: if one fell, all could be dragged down.

Imperialism supplied both the rivalries and the arrogance. The great powers competed for colonies and prestige across Africa and Asia, and repeated crises—over Morocco, over the Balkans—taught them to see the world as a zero-sum contest. And nationalism lit the whole thing from within: a fierce pride in one's own nation, and among subject peoples, a burning desire for a nation of their own.

By 1914 the great powers were like men standing in a room full of gunpowder, each holding a lit torch and watching the others. They did not necessarily want a general war. But they had built a world in which one could ignite almost by itself—and in which each, once it began, would feel it had no choice but to strike. That spark would come on a June morning in a Bosnian city, from a nineteen-year-old with a pistol.

On the morning of Sunday, 28 June 1914, Archduke Franz Ferdinand, heir to the throne of Austria-Hungary, rode into the Bosnian capital of Sarajevo in an open car beside his wife, Sophie. It was their wedding anniversary. It was also, by grim coincidence, St. Vitus's Day—Vidovdan—a date sacred to Serbian nationalists, who marked on it the medieval defeat of Serbia by the Ottomans. To bring the symbol of Habsburg power into Sarajevo on that day struck many Serbs as a provocation.

Waiting along the route were several young members of a Bosnian-Serb revolutionary cell, armed with bombs and pistols supplied through a shadowy Serbian secret society known as the Black Hand. They wanted Bosnia freed from Austria-Hungary and joined to a greater Serbian or South Slav state. The morning's first attempt failed almost farcically: one conspirator, Nedeljko Čabrinović, hurled a bomb at the motorcade. It bounced off the folded roof of the Archduke's car and exploded under the vehicle behind, wounding officers and bystanders. The Archduke drove on to the town hall, shaken and furious.

What happened next turned on chance. After the reception, the Archduke decided to visit the wounded in hospital, and his party set off again. But no one had clearly told the drivers of the changed route. The lead cars turned down a side street; when the mistake was realized, Franz Ferdinand's driver, Leopold Lojka, stopped and began to reverse—directly in front of a delicatessen where Gavrilo Princip happened to be standing. The assassin could not believe his luck. He stepped forward, raised his pistol, and fired twice at point-blank range.

The murder of an archduke would, in another age, have been a tragedy confined to one family and one empire. But in the Europe of 1914, it was a lit match dropped into that room full of gunpowder. Austria-Hungary now had what its leaders had wanted: a reason to crush Serbia. Over the next five weeks, a local crime metastasized into a world war—not because any leader coolly chose it, but because a generation of alliances, fears, and war plans took over. Historians call those weeks the July Crisis, and they remain one of history's great cautionary tales about how quickly the unthinkable can become the unstoppable.

Austria-Hungary did not rush. For weeks its leaders debated how to respond, and above all they sought assurance from their powerful ally, Germany. In early July, the Kaiser and his chancellor gave it: the famous "blank cheque," a promise of full German support for whatever action Vienna took against Serbia. Emboldened, Austria-Hungary drafted an ultimatum designed to be impossible to accept.

Delivered on 23 July, it made ten sweeping demands, including that Austrian officials be allowed to operate inside Serbia to suppress anti-Habsburg movements. Serbia's reply, two days later, was strikingly conciliatory—it accepted nearly every point. It was not enough. Austria-Hungary declared the answer inadequate and, on 28 July 1914, declared war on Serbia. The local conflict everyone had feared was now real. The question was whether it would stay local. It would not.

Now the alliance system did exactly what critics had feared. Russia, protector of the Slavs and of Serbia, began to mobilize its vast army. Germany, terrified of being caught between France and Russia, demanded Russia stop; when it did not, Germany declared war on Russia on 1 August, and on Russia's ally France on 3 August. Everything then hinged on a plan drawn up years earlier by the German general staff.

Britain had guaranteed Belgian neutrality by a treaty dating to 1839. When German troops crossed the Belgian frontier on 4 August, Britain demanded their withdrawal; Germany refused. The German chancellor reportedly dismissed the old treaty as a mere "scrap of paper." That evening, Britain declared war. The war was now between empires spanning the globe. On the same night, according to his own memoir published years later, the British foreign secretary, Sir Edward Grey, stood at his window watching the London street-lamps being lit and spoke words that would become the war's epitaph.

The soldiers who marched off in August 1914 believed they would be home by Christmas. Crowds cheered them at railway stations; the mood in many capitals was closer to festival than dread. Almost everyone imagined a short, decisive war of movement, like the wars of the previous century. Almost everyone was wrong.

The German armies swept into Belgium and northern France with terrifying speed, brushing aside the Belgian defenders and colliding with the French and the small British Expeditionary Force. The German advance was shadowed by brutality against Belgian civilians—executions, burned towns, the destruction of the great library at Louvain—that Allied propaganda would call the "Rape of Belgium," and that horrified neutral opinion, including in the United States. Meanwhile France's own war plan, a doctrine of headlong attack, sent French soldiers in their conspicuous red trousers charging into modern rifle and machine-gun fire. The result was slaughter: France suffered staggering casualties in the opening weeks, and the Germans drove to within sight of Paris. The French government fled to Bordeaux.

What followed was one of the strangest episodes in military history. Having failed to break through, each side tried to outflank the other by marching north and west toward the sea. Again and again they collided, dug in, and tried again farther on. This "Race to the Sea" ended only when the armies reached the Belgian coast with nowhere left to go. By late 1914, an unbroken line of trenches stretched roughly four hundred and fifty miles, from the North Sea across Belgium and France to the Swiss border. There were no flanks left to turn. The war of movement was over.

Both sides now faced a problem no general had truly prepared for: how to attack an enemy who was dug into the earth, screened by barbed wire, and defended by machine guns and artillery. Their answers, over the next four years, would cost millions of lives. The trenches had arrived, and they would define the war.

The word "trench" hardly conveys what it became. What began as shallow scrapes in the ground grew into vast, permanent systems—front-line trenches, support trenches, and reserve trenches behind them, linked by communication trenches and dug in zigzags so that a shell or an enemy could not sweep a whole length at once. Between the opposing lines lay no man's land: a churned waste of mud, shell craters, tangled barbed wire, and the unburied dead, sometimes a few hundred yards across, sometimes only a stone's throw.

Life in the trenches was a grinding misery punctuated by terror. Men lived among rats grown fat on corpses, and among lice that no amount of picking could defeat. In wet weather the trenches flooded, and soldiers standing for days in cold water developed "trench foot," a rotting of the flesh that could cost them their toes or their feet. Above all there was the artillery. Contrary to the popular image of men mown down charging machine guns, it was shellfire—the relentless, random, earth-shaking bombardment—that killed and maimed the most. A soldier could be blown apart while doing nothing at all, and the constant shelling produced a new affliction the doctors struggled to name: "shell shock," what we would now recognize as psychological trauma.

The cruel arithmetic of trench warfare was that defense had become far stronger than attack. To advance, men had to climb "over the top" and cross open ground raked by machine guns and pre-registered artillery, against an enemy sheltering in deep dugouts. Generals on both sides, trained for a different kind of war, spent years hurling infantry against these defenses in the hope of a breakthrough that almost never came. The front line would shift by a few miles, then freeze again, at a cost of tens of thousands of lives.

And yet, amid the horror, the humanity of ordinary men sometimes broke through. The most famous instance came in the war's very first winter.

The truce could not last, because the war that produced it did not care about the men fighting it. High commands on both sides made sure such fraternization never happened again, and the killing resumed. As 1914 gave way to 1915, the two sides settled into the long, murderous stalemate—and began, urgently, to search for weapons that might break it.

The First World War was the first great war of the industrial age, and industry now turned its full genius to killing. The factories that had promised progress produced instead an arsenal of machines whose only purpose was to kill human beings faster than ever before. This was the deeper horror of the war: not merely that so many died, but that they died on an assembly line.

The machine gun was its emblem. A single weapon, served by a handful of men, could fire hundreds of rounds a minute and scythe down attacking infantry in swathes. The artillery was worse still—heavier, more numerous, and more accurate than in any previous war, capable of turning a landscape into a cratered moonscape and a human body into nothing at all. Between them, the machine gun and the gun defined the killing power of the trenches. And then, in 1915, came a weapon so dreadful that the world recoiled even in the middle of a war.

Poison gas killed fewer men than artillery or bullets, and armies quickly developed gas masks. But its psychological effect was out of all proportion to its body count. To be gassed was to die slowly and helplessly, and the terror of it haunted the survivors. No one wrote of that terror more unforgettably than a young British officer and poet named Wilfred Owen, who described a comrade dying in a gas attack—and then turned his fury on the old patriotic slogans that sent boys to such deaths.

Owen said his poetry was not about heroism but about pity: "My subject is War, and the pity of War," he wrote in a draft preface. He was one of a generation of soldier-poets—alongside men like the Canadian officer John McCrae, whose "In Flanders Fields" made the red poppy the enduring emblem of the war's dead—who found that the old language of glory no longer fit what they had seen. The industrialization of killing had changed not only how men died, but what it was possible to believe about war itself.

While the Western Front congealed into trenches, the war in the east was a different beast. Here the distances were vast, the fronts were fluid, and armies swung back and forth across hundreds of miles of Poland, Galicia, and the Russian borderlands. Russia had mobilized faster than Germany expected and thrust two armies into East Prussia in August 1914, hoping to relieve pressure on its French ally. It very nearly worked—and then it went catastrophically wrong.

Germany's response made two men into national heroes. At the Battle of Tannenberg, late in August 1914, German forces surrounded and destroyed an entire Russian army; tens of thousands were killed and roughly ninety thousand taken prisoner. Its commander, General Alexander Samsonov, walked into the woods and shot himself rather than report the disaster to the Tsar. A follow-up victory at the Masurian Lakes drove the Russians out of East Prussia entirely.

Yet the east was not all German triumph. Against Austria-Hungary, the Russians did far better, overrunning much of the province of Galicia. The Habsburg army, straining to hold together its dozen nationalities, bled badly and increasingly leaned on German support. The Eastern Front became a seesaw of advances and retreats that ground up men on a scale to rival the west—but for Russia, the deeper story was one of mounting strain: shortages of rifles and shells, staggering casualties, and a home front sliding toward collapse.

The war widened in other directions, too. In the autumn of 1914 the Ottoman Empire—still vast, spanning Anatolia, the Arab lands, and the Middle East—entered the war on the side of Germany and Austria-Hungary. That decision turned the conflict into a genuinely world war, opening new fronts across the Middle East and the Caucasus. It went badly at once for the Ottomans in the mountains: a winter offensive against Russia in the Caucasus, driven by the war minister Enver Pasha, ended in a frozen disaster at Sarıkamış, where much of an Ottoman army perished in the snow. But the Ottoman entry also created a tempting target for the Allies—a soft "underbelly" they hoped to strike. In 1915 they tried, at a peninsula called Gallipoli.

The idea was bold, and on paper it was brilliant. If the Allies could force the Dardanelles—the narrow strait guarding the sea route to Constantinople—they might knock the Ottoman Empire out of the war, open a supply line to hard-pressed Russia, and break the deadlock of the Western Front from the side. Its most energetic champion was Winston Churchill, then First Lord of the Admiralty. It would become one of the war's most famous failures.

The naval attack came first, in early 1915, and it foundered on Ottoman mines and shore batteries, with several Allied battleships sunk or crippled. So the Allies turned to a land invasion of the Gallipoli peninsula. On 25 April 1915, troops went ashore—British and French forces at Cape Helles, and the soldiers of the Australian and New Zealand Army Corps, the ANZACs, at a cove that would take their name. They found not a quick victory but the same horror as the Western Front, transplanted to steep, sun-baked cliffs: entrenchment, machine guns, disease, and stalemate.

For eight months the two sides clung to the peninsula, dying in their thousands from bullets, shells, and the dysentery and heat that ravaged both armies. Neither could break the other. In the end, the only unqualified Allied success at Gallipoli was the withdrawal: in December 1915 and January 1916, the troops were evacuated so skillfully, and so quietly, that the Ottomans scarcely noticed them go. The campaign had cost something like half a million casualties on both sides combined, and achieved nothing strategically.

The disaster had a political price as well: Churchill, blamed for the fiasco, was forced from the Admiralty and into the political wilderness—a fall from which, decades later, he would famously recover. But the lesson of Gallipoli was grimmer than any one career. Even the boldest attempt to outflank the stalemate had failed. There was, it seemed, no clever way around the killing. The war would be decided the hard way, on the main fronts—and 1916 would show just how hard that would be.

If any year distilled the horror of the First World War into a single, unbearable image, it was 1916. In that year two battles—one German-led, one British-led—consumed more than a million men between them and moved the front line by only a handful of miles. They were not battles in the old sense of a clash to be won. They were engines of attrition, designed to kill more of the enemy than they cost, and they revealed the terrible logic to which the war had descended.

The first was Verdun. In February 1916 the German army launched a massive offensive against the ring of French fortresses around the city of Verdun—a place of immense symbolic value to France. The German commander, Erich von Falkenhayn, later claimed his aim had never been to take Verdun but to "bleed France white," to force the French to feed men into a mincing machine until their army collapsed.

The French, under General Philippe Pétain, held on with grim determination, rushing men and supplies up a single road that became known as the "Sacred Way." Their defiant slogan—"Ils ne passeront pas," They shall not pass—became a national watchword. The battle raged for most of the year. When it finally guttered out in December, the French had held, and the combined casualties are estimated at somewhere around seven to eight hundred thousand men, killed and wounded, for almost no change in the line.

To relieve the pressure on Verdun, the British launched their own great offensive on the River Somme. It began on 1 July 1916 with a week-long bombardment meant to obliterate the German defenses. It did not. When the whistles blew and the British infantry climbed out and walked toward the German lines, they were met by machine-gunners who had sheltered deep underground and now emerged to cut them down.

Presiding over the British effort was General Sir Douglas Haig, whose willingness to keep feeding men into such battles has made his name a byword for callous generalship. Historians still argue over him: some see a butcher indifferent to loss, others a commander wrestling, like all his peers, with an unprecedented and near-insoluble problem. What no one disputes is the toll. By the end of 1916, the men who fought had few illusions left. The war had become a machine for killing, and it was nowhere near finished.

The war was not only fought in the mud. At sea, Britain wielded the greatest navy on earth to strangle Germany's trade, imposing a blockade that slowly cut off food and raw materials from the Central Powers. That blockade would, over the war's course, contribute to the deaths of hundreds of thousands of German civilians from malnutrition and its effects—an unglamorous, patient form of warfare that helped decide the outcome as surely as any battle.

Germany's answer was twofold. Its surface fleet challenged the Royal Navy just once in a major clash, at the Battle of Jutland off the coast of Denmark on 31 May and 1 June 1916. It was the largest naval battle of the war—hundreds of ships, thousands of men. The Germans sank more British tonnage and could claim a tactical victory, but strategically they lost: their High Seas Fleet retreated to port and never seriously challenged the blockade again. Britain still ruled the waves.

So Germany turned to the weapon that would nearly win the war and ultimately help lose it: the submarine, the U-boat. Prowling beneath the surface, U-boats could sink merchant ships without warning—a terrifyingly effective tactic that also outraged neutral opinion, because it drowned civilians.

There is another chapter of this war that must be told plainly, because it belongs to history and because the dead deserve to be remembered. As the Ottoman Empire fought for survival, its government carried out a systematic campaign of deportation and mass murder against its Armenian population—a Christian minority it accused, largely without foundation, of collaborating with the enemy. Beginning in the spring of 1915, Armenian leaders and intellectuals were arrested, and the wider population was driven from their homes on death marches into the Syrian desert, where vast numbers died of starvation, exposure, and outright massacre.

These are among the first mass atrocities of the twentieth century to be documented as they happened, by diplomats, missionaries, and survivors. They are also a reminder that the First World War was not only a war of soldiers against soldiers. Under its cover, whole peoples could be targeted for destruction—a horror the century would see again on an even greater scale. To tell the story of this war honestly, we cannot look away from it.

Nineteen seventeen was the year the war changed shape. Two events, thousands of miles apart, transformed the entire strategic picture: the United States entered the war, and Russia left it. Together they set the stage for the war's final act, and for much of the century to come.

America's road to war ran through the U-boat. Desperate to break the British blockade and win before the Allies could grind them down, Germany's leaders made a fateful decision: on 1 February 1917, they resumed unrestricted submarine warfare, ordering their U-boats to sink any ship—including neutral American vessels—bound for Allied ports. They knew it might bring the United States into the war, and gambled they could starve Britain into surrender first. Then came a second blunder that removed all American doubt.

President Woodrow Wilson had won re-election in 1916 on the boast that he had "kept us out of war," and had called as recently as January 1917 for "peace without victory." Now he took his country to war—but he framed it in soaring, idealistic terms, as a crusade not for conquest but for principle.

American troops—the American Expeditionary Forces under General John J. Pershing—would take time to arrive in strength; their weight would not be fully felt until 1918. But the promise of a fresh, enormous, industrially mighty ally was a transfusion of hope for the exhausted Allies, and a shadow over Germany. And it fell just as the other great event of 1917 was pulling Germany's most populous enemy out of the fight.

So the race was on. Russia's collapse freed hundreds of thousands of German troops for the Western Front, and Germany's generals knew they had a narrow window—perhaps a few months—to win the war before the Americans arrived in overwhelming numbers. In the spring of 1918, they would throw everything into that gamble.

This was a war that reached into every home. Earlier wars had been fought by armies while civilians watched from a distance; this one demanded the labor, the wealth, and the belief of entire nations. Historians call it "total war"—a struggle in which the whole society, not just its soldiers, was mobilized for victory. And that mobilization changed the world almost as much as the fighting did.

With millions of men at the front, women stepped into the jobs they left behind. They poured into the munitions factories—the "munitionettes," whose skin sometimes turned yellow from the explosives they handled—and worked the farms, drove the buses, and nursed the wounded. This vast entry of women into the workforce did not, by itself, win them the vote. But it made the old arguments against it harder to sustain. In Britain, women over thirty gained the vote in 1918; in the United States, the constitutional amendment for women's suffrage followed in 1920. The war had cracked open a door that would not close again.

The state grew enormous. Governments took control of industries, rationed food, conscripted men, and censored the press. Propaganda blanketed the home fronts—posters, films, and newspapers stoking hatred of the enemy and demanding sacrifice. In Germany, the Allied blockade bit hard: the terrible "Turnip Winter" of 1916–17 saw civilians reduced to eating fodder turnips as bread and potatoes ran out. War was no longer something that happened only to soldiers.

And the war truly was a world war. The great empires drew soldiers and labourers from across the globe: Indians, Africans, Vietnamese, Chinese, and men from every British dominion fought and died in Europe and beyond. Campaigns raged across the deserts of the Middle East, where British and Arab forces battled the Ottomans and captured Jerusalem and Baghdad, and across Africa, where a small German force led by Paul von Lettow-Vorbeck evaded capture until the very end. The men who came from the colonies to fight and die for their imperial rulers would return home with new expectations—and the war would help set in motion the long unraveling of the empires that had summoned them.

By the spring of 1918, Germany's leaders knew their window was closing. Russia was out of the war, freeing their eastern armies, but the Americans were coming, and the British blockade was strangling the home front. General Ludendorff, by now the dominant figure in the German command, resolved to stake everything on one last, colossal offensive to win the war in the west before American strength became overwhelming.

The blow fell on 21 March 1918. In a series of assaults known as the Spring Offensive—or the Kaiserschlacht, the "Kaiser's Battle"—the Germans unleashed hurricane bombardments and fast-moving "stormtrooper" infantry that infiltrated the Allied lines rather than battering them head-on. It worked, at first, spectacularly. The German army tore great holes in the front and advanced dozens of miles, the deepest gains by either side since 1914. Their long-range guns even shelled Paris. For a few weeks it looked as though Germany might actually win.

But the offensive carried the seeds of its own defeat. The Germans advanced faster than their supplies could follow; their best troops were killed in the very success of the attack; and the ground they took was a ruined wilderness that could not be held cheaply. The line bent, but it did not break. Then, in the summer, the tide turned for good, as fresh American divisions poured into the fight and the Allies—now under a single supreme commander, the French marshal Ferdinand Foch—began to push back.

Now the whole edifice of the Central Powers came apart. Bulgaria surrendered at the end of September; the Ottoman Empire signed an armistice at the end of October; and Austria-Hungary, its many nationalities breaking away to form new nations, collapsed and sued for peace in early November. Germany stood alone, its army retreating and its people starving.

Then Germany itself began to crack. When the naval command ordered the fleet out for a last, suicidal battle, the sailors mutinied at Kiel, and revolution spread through the country. With his generals telling him the war was lost and his throne no longer safe, Kaiser Wilhelm II abdicated on 9 November 1918 and fled into exile in the Netherlands. A German republic was proclaimed. The empire that had gambled on a short, victorious war had lost everything—and its new leaders now had to ask the Allies for terms.

The end, when it came, came in a railway carriage in a forest. In the small hours of 11 November 1918, a German delegation led by the politician Matthias Erzberger sat across from Marshal Foch in his private train, parked in a clearing in the forest of Compiègne, north of Paris, and signed the armistice. The terms were harsh—Germany was to evacuate occupied lands, surrender vast quantities of weapons and ships, and submit to the continued blockade—but the guns were to fall silent. The signing was done by around five o'clock in the morning. The ceasefire would take effect at eleven.

And then the world began to count its dead. The numbers are so large that they slide past comprehension, and they are genuinely uncertain—compiled from broken records, across collapsing states, in a chaos that no ledger could fully capture. Historians give ranges, not exact figures, and honest history respects the difference.

Overlapping the war's final year came a second catastrophe: a savage strain of influenza, misleadingly nicknamed the "Spanish flu," that swept the globe in 1918–19. Spread by the vast movements of troops and worsened by wartime conditions, it killed on a scale that dwarfed even the battlefields—tens of millions of people, young and healthy among them. For millions of families, the misery of the war and the terror of the pandemic arrived as a single, unending blow.

There is one small, devastating story that captures the whole. Wilfred Owen, the poet who had branded the glory of dying for one's country "the old Lie," was killed in action on 4 November 1918—just seven days before the Armistice. As the church bells of his hometown rang out to celebrate the war's end on 11 November, his mother received the telegram informing her that her son was dead. The joy of the world's deliverance and the private grief of a family arrived, for her, in the very same hour. Multiply that grief by the millions, and you begin to grasp what the war had cost.

The war was over, but the peace remained to be made—and the peace would prove almost as fateful as the war. In 1919 the victors gathered in Paris to remake the world, dominated by the "Big Four": Woodrow Wilson of the United States, David Lloyd George of Britain, Georges Clemenceau of France, and Vittorio Orlando of Italy. They pursued clashing aims. Wilson dreamed of a just, lasting settlement and a new world order; Clemenceau, whose country had been invaded and bled twice in fifty years, wanted Germany crushed so it could never do so again.

The result, the Treaty of Versailles, was signed on 28 June 1919—five years to the day after the shots at Sarajevo—in the Hall of Mirrors of the palace of Versailles, the very room where the German Empire had been proclaimed in triumph in 1871. The symbolism was deliberate, and for Germans it was humiliating. The treaty stripped Germany of territory and all its colonies, slashed its army, and, in the notorious Article 231—the "War Guilt Clause"—forced it to accept responsibility for the war as the basis for enormous reparations payments.

Wilson's cherished creation, the League of Nations, was written into the treaty—the first true attempt at a global organization to keep the peace. Yet in a bitter irony, Wilson's own country refused to join it: the United States Senate rejected the treaty, and America retreated toward isolation, robbing the League of its most powerful potential member. It was crippled from birth.

The deeper problem was that the peace satisfied no one. To the French, it was too soft; to the Germans, it was a monstrous "Diktat," a dictated humiliation they had never agreed to, and the myth soon spread that Germany's army had been "stabbed in the back" by traitors at home rather than beaten in the field. Onto this soil of resentment and economic ruin, over the next two decades, a new and even darker force would grow. Some who saw the treaty understood this at once.

For the story of how that resentment curdled into catastrophe—how the failed peace, the Great Depression, and a bitter, defeated nation gave rise to Adolf Hitler and the Second World War—we hand you on to a separate telling: World War II. This story ends where that one begins.

They had called it "the war to end all wars"—a hopeful phrase drawn from the writer H. G. Wells and taken up by Wilson and others—as if such horror, once endured, could never be repeated. It was the cruelest illusion of all. The war had not ended war; it had reloaded it. But it had ended something else forever: the confident, glittering, monarchical world of 1914, with its faith in progress and its certainty that reason would keep the peace. That world went into the trenches in August 1914 and never came out. What emerged, at appalling cost, was our own.