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The World War I Battle That Changed the World Forever

105 years ago, a decisive engagement on the Marne River transformed warfare, destroyed Europe, and unleashed totalitarianism.

When World War I broke out in August 1914, it was assumed that it would be over quickly. In six months, perhaps as early as Christmas, one side or the other would deliver what would later be called the “knockout blow.”

“Before the leaves fall, you will be home,” German Emperor William II was quoted as saying to the troops leaving for the front. The leaves would fall for another four years along with millions of Europe’s finest young men in what would be the most destructive European conflict since the Thirty Years War of the 17th century.

The course of this awful war was set by a battle little known in the United States. The Battle of the Marne, which began 105 years ago today and lasted for about one week, ranks alongside Waterloo, Stalingrad, and Gettysburg as among the most decisive engagements in modern history. In many ways it shaped the course of the 20th century.

The German war plan, called the Schlieffen Plan after the Prussian General who devised it a decade earlier, envisaged a quick victory while the French armies were mobilizing. Five German armies, spread from the English Channel to the French-Swiss frontier, would swing like a scythe through northern France with the aim of passing behind Paris and trapping the French armies with their backs to the city’s main fortifications.

The plan began to break down almost from the beginning. Belgium refused permission for the German troops to pass through its territory, forcing German troops to spend five days eliminating Belgian resistance. They did so with a degree of brutality that would become commonplace in the future—612 men and women were shot in Dinant and the great library in Louvain was burned down. 

The rapidly mobilizing French armies, joined by a small professional British force known as the “Old Contemptibles,” retreated through northwestern France, all the while taking a toll on the invading Germans. At a skirmish near the village of Mons, the Germans believed they were facing English machine gunfire. It was in fact the sustained rifle fire that the professional British army was famous for—a shot every four seconds. The losses on both sides were shockingly high for a brief engagement, foreshadowing what the war would later bring.

By the end of August, the German forces were approaching Paris, but French and British counter-attacks forced them to modify their war plan. Responding to this military pressure and the exhaustion of moving five armies 200 miles in the midst of the August heat, the main German force would now pass in front of Paris. More importantly, a 20-mile gap opened between the two German armies north and west of Paris along the river Marne, the result of six weeks of constant fighting. Into this gap, the French commander, General Joseph “Papa” Joffre, launched a desperate counter-attack on September 6. In one of the most famous incidents of the war, troops from the Paris garrison were delivered to the front in 600 taxicabs. 

On September 13, after a week of desperate, even vicious, fighting, the German forces retreated 30 to 40 miles, and began building trenches along the Aisne River. A French counter-attack failed to dislodge them and both sides dug in along the river, the beginning of the trench line that would eventually extend from the Swiss frontier to the French coast. The front would move little more than a few miles in either direction for the next four years, at a terrible cost in human lives.

The Battle of the Marne proved historically decisive—the French referred to it as “The Miracle of the Marne.” The German commander, General Helmuth von Moltke, told the German Emperor afterwards that the war was lost. He suffered a nervous breakdown and had to be relieved of his command.

Six weeks of fighting cost both sides about a quarter of a million casualties, numbers that had been beyond the imagination before the war began. Instead of the short, decisive victory that everyone expected, the fighting now settled into a deadly pattern. On the Western front, as it became known, both sides constructed an elaborate series of defensive fortifications that grew in depth and complexity, setting the stage for the warfare that followed. Large-scale frontal attacks in which the defense prevailed created a deadlock along with a terrible toll in human lives. The course of World War I was set. Huge pitched battles not seen before in European history followed: Verdun, the Somme, Ypres. Neither side could prevail.

New weapons systems emerged. The machine gun wreaked havoc on the battlefield and became the weapon of choice for infantry, inflicting horrific losses as attackers tried to cross the fittingly named “no man’s land.” The airplane, invented just a decade earlier, became invaluable for conducting battlefield observations. By the end of the war, all the major participants had large air forces, and bombing, which at first consisted of dropping bombs by hand, became increasingly sophisticated, foreshadowing the great air raids of the Second World War. 

Poison gas was used, first by the Germans and then by both the French and British, as a way of overcoming the battlefield stalemate. It also failed but those exposed suffered terrible injuries. Nothing brought victory and the battle deaths kept rising. A conservative figure for the four years that followed is 10 million killed and 20 million injured.

There was another price to be paid: the complex civilization that the Europeans had created since the Renaissance—the free flow of money, goods, and people across the continent, the growing prosperity that spread throughout the West during the 19th century—came to sudden halt. In its place was a blood-soaked continent, European currencies rendered almost worthless, bitter class and social hatred that poisoned human relations, along with the collapse of four great empires: Germany, Austria-Hungary, Russia, and Ottoman.

Perhaps one of the worst by-products of the war was the rise of totalitarianism, as governments seized full control of societies. It is impossible to conceive of the success of the Russian Revolution and eventual communist dictatorship, or the rise of Mussolini’s fascism, without the chaos left by World War I. Even more tragically, Germany’s defeat laid the groundwork for the rise of Hitler’s Nazi movement and sowed the seeds for an even more horrible conflict, World War II, which included something unprecedented: the attempted destruction of an entire race in the Holocaust.

From the German failure at the Marne flowed consequences that no one could have foreseen. It was one of those battles that truly changed the course of history.

John P. Rossi is professor emeritus of History at La Salle University in Philadelphia.