A century ago, the peace conference convened that drafted the Versailles Treaty. It was a time of hope. World War I, then variously called the Great War, the War to End War, and the War for Democracy, had mercifully ended. The worst conflict in modern history had yielded mass death, destruction, and chaos. Now a new world would be built.

Unfortunately, we are still living and suffering in that world. Today’s social engineers are pikers compared to the sanctimonious, hypocritical megalomaniacs who in early 1919 sought to reorder the globe to their fantasies. In doing so, they planted the seeds of World War II a generation later, as well as innumerable smaller conflicts in succeeding decades. Their legacy warns us against the modern Sirens who insist that America’s responsibility is to reorder the world, enforced by constant war if necessary.

On June 28, 1914, Serbian Gavrilo Princip, armed by nationalist government officials, fired what may been the two most consequential gunshots in history, when he assassinated the heir apparent to the Austro-Hungarian throne on the streets of Sarajevo in Bosnia-Herzegovina. Princip thereby loosed Europe’s many fears, hatreds, ambitions, and fantasies, and within weeks armies were on the march. Eventually, more distant nations, most notably the U.S. and Japan, joined in. Princip did not survive the war, dying of tuberculosis in prison, but his handiwork left at least 20 million people dead, four ancient empires in ruins, widespread economic destruction, mass social dislocation, multiple violent revolutionary movements active and dangerous, and conflict still raging in Europe’s east, across Russia, and throughout the Caucasus and Middle East.

On January 18, 1919, the allies gathered in Paris—though the treaty would be signed in June at the Versailles palace, most of the negotiations took place in the French foreign ministry’s more mundane surroundings. French Prime Minister Georges Clemenceau, a tough, ruthless nationalist who bore much of the credit for his nation’s victory, admitted, “Making peace is harder than waging war.” In contrast to the aftermath of the Napoleonic Wars, the losers were excluded. In fact, Austria-Hungary and the Ottoman Empire had ceased to exist and the Hohenzollern monarchy had been extinguished. The representatives of their democratic successor states, most importantly Germany, were to be dictated to rather than reasoned with.

The story of the succeeding five months has been told in excruciating detail. The “Big Four”—Clemenceau, Italy’s Prime Minister Vittorio Orlando, Great Britain’s Prime Minster David Lloyd George, and America’s President Woodrow Wilson—dominated the proceedings. Wilson refashioned the war as a crusade, and many around the world looked to him and the ideals he espoused. The haughty, sanctimonious, and ignorant Wilson would turn out to be uniquely pernicious. His realpolitik counterparts wearied of his claim to speak for humanity. Of his famed 14 Points, Clemenceau snarled, “the good Lord only had 10.” Wilson later admitted to not knowing that millions of ethnic Germans remained in Czechoslovakia’s Sudetenland. Two decades later, their status became Adolf Hitler’s excuse for breaking up that nation.

Despite the high-flown rhetoric, most of the participants fought for their own nations’ or peoples’ interests. The conference provided an opportunity for high-minded plunder and grandiose plans for social engineering. The Germans would be made to pay for the war, despite the shared responsibility for the conflict’s start. New ethnic-based states would be created, containing populations of dissatisfied groups on the losing side. Some of these new entities, especially in the Middle East, would be turned into glorified colonies in the form of “mandates,” the formal responsibilities for which Wilson’s negotiating partners unabashedly giggled when discussing. And Wilson’s hallowed League of Nations would be used to enforce the victors’ peace in the years ahead.

Critics were many. France’s Marshal Ferdinand Foch, the allied commander-in-chief at war’s end, wanted harsher terms. He lamented: “This is not peace. It is an armistice for 20 years.” South African General Jan Smuts, who served on the peace delegation and became prime minister shortly after his return, criticized forcing Germany to sign at the “point of the bayonet,” adding that “a new international order and a fairer, better world are not written into this treaty.” John Maynard Keynes, before he gained global economic fame, opined: “The campaign for securing out of Germany the general costs of the war was one of the most serious acts of political unwisdom for which our statesmen have ever been responsible.”

Alas, the Rube Goldberg scheme created by witlessly hubristic planners came apart almost immediately. On the ground, nationalists ignored the pronouncements of foreign leaders signing documents in the fabled Hall of Mirrors hundreds and thousands of miles away. Despite the allies’ grand victory, there would be no military expeditions to enforce every jot and tittle of the treaty.

The Russians were excluded as a bitter, brutal civil war consumed their great land. Despite halfhearted allied intervention, the Bolshevik state triumphed, creating a new menace to the east. Americans were disillusioned with both the Europeans and their president. Wilson had negotiated without consulting Republican senators, who rejected his all-or-nothing demand, leaving America outside of the vaunted League of Nations.

The French and Belgians were frustrated. Determined to weaken Germany, they sought to harshly enforce Versailles’ dictates on the recalcitrant Germans. But over time they found themselves alone. The British were disappointed, convinced that accommodation of Berlin would be better policy, and soon refused to back their allies. The Italians were victors, but nevertheless dissatisfied, and soon turned to Benito Mussolini.

Most importantly, the Germans were resentful, having had no say in their own fate. Opposition to Versailles rallied both supporters and opponents of the weak new democratic order, but most benefited the latter. German governments variously resisted the treaty’s terms and sought reconciliation, as the political system imploded amid the Great Depression with the rise of both Nazis and communists. On January 30, 1933, just 14 years after those in Versailles gathered to create a new peaceful order, Adolf Hitler became chancellor of the wealthiest, most populous, and most militarist nation in Europe. The rest, as they say, is history.

By the late 1930s, many of Versailles’ requirements had been reduced to dead letters by German aggression and allied acquiescence. Tragically, the victors had fallen between two stools, willing neither to ruthlessly impose a Carthaginian peace nor to reconcile with the new democratic republic.

The ensuing global conflagration wiped away additional aspects of the Versailles order. And the end of the Cold War and collapse of the Soviet Union would complete the destruction of Versailles. Moscow’s de facto colonies had broken free. The Balkans were reordered into what Germans long before had called Saisonstaaten, or “states for a season,” transforming and disappearing. Ironically, what eventually emerged looks a lot like the hated Brest-Litovsk Treaty imposed by imperial Germany on the struggling Bolsheviks. It enshrined German dominance and broke up the Russian Empire, freeing 11 nations from Soviet control (though expecting them to be subjects, even vassals, of Berlin). The treaty was voided by the allies, though today even Brest-Litovsk looks more realistic than Versailles.

A similar process of disintegration transformed the Middle East. Lebanon, Syria, Iraq, Israel, Saudi Arabia, and the other Gulf states emerged out of the wreckage of the Ottoman Empire and British-French line-drawing. Gradually the allies departed, forced out by the aftermath of World War II and rising Arab nationalism. The existing states may survive, but not as stable, united, democratic systems. Some may end up as countries in name only. How the region would have evolved absent the efforts of the allied “peacemakers” is impossible to know. But it would have taken effort to have yielded worse results.

Yet a century later, voices continue to insist that Washington engage in additional military interventions, line-drawing, and global social engineering. Hopefully political leaders will eventually learn from the disastrous experience of 1919.

Doug Bandow is a senior fellow at the Cato Institute. A former special assistant to President Ronald Reagan, he is author of Foreign Follies: America’s New Global  Empire.