When World War I erupted, Germany faced a daunting strategic predicament. Encircled by the Franco-Russian Alliance, with Austria-Hungary as its sole major ally, Germany appeared destined for a protracted and potentially losing war. However, the German military in 1914 harbored confidence in a swift victory. In August, they initiated a sweeping offensive through Belgium, overwhelming Allied forces in a series of battles and pushing Germany to the cusp of triumph.
Yet, as Paris loomed within reach, the momentum shifted dramatically. A Franco-British counteroffensive at the Battle of the Marne compelled the German forces to retreat, shattering their aspirations for a rapid resolution to the conflict. This pivotal moment begs the crucial questions: What precipitated the failure of the German plan? And how close did Germany truly come to achieving its objectives?
To comprehend the unraveling of Germany’s strategy, a detailed examination of the Schlieffen Plan is essential.
The Genesis of the Schlieffen Plan: A Strategy for Swift Victory
Germany’s precarious strategic position had been apparent since the early 20th century. Recognizing the German economy’s vulnerability to a prolonged war, Field Marshal Alfred von Schlieffen, then Chief of Staff of the German Army, devised a strategy aimed at achieving a decisive victory in short order. This strategy became known as the Schlieffen Plan.
Von Schlieffen’s rationale rested on the belief that Russia’s mobilization would lag behind that of France. Consequently, he proposed concentrating the overwhelming majority of German forces on a swift and decisive campaign in the West. Once France was vanquished, Germany could then pivot its entire military might eastward to confront the Russian army.
However, a significant obstacle lay in France’s formidable fortifications along its border with Germany. Directly assaulting these defenses before Russia fully mobilized would be a costly and potentially futile endeavor. Therefore, von Schlieffen opted for a high-risk flanking maneuver through the neutral Low Countries – the Netherlands, Belgium, and Luxembourg. By concentrating the bulk of their forces on the far-right wing, the German plan aimed to encircle Paris and drive the remaining French armies into submission.
This ambitious plan was not without inherent dangers. Invading neutral Belgium risked drawing Great Britain into the war. More critically, failure would mean Germany squandering vital manpower and resources, resources desperately needed for the looming two-front war. These risks prompted von Schlieffen’s successor, Helmuth von Moltke the Younger, to implement modifications to the original plan.
Military historian Bryn Hammond notes, “The German army hierarchy certainly wanted a quick victory and adopted a plan that might perhaps deliver one, but that doesn’t mean that they didn’t take sensible precautions. When war came, their campaign plan involved many elements predicated on a prolonged conflict. They excluded southern Holland from the path of the German offensive thrust. They protected Alsace and the Lorraine iron ore fields from French re-conquest; and they placed an army corps in East Prussia to stem the anticipated Russian advance. If a quick victory was not achieved, these measures offered a sensible insurance against the difficulties of a protracted struggle. But the danger of these changes was that they made a short war even harder to deliver.” These modifications, while intended to mitigate risk, inadvertently diluted the offensive power of the crucial right flank, which was central to the Schlieffen Plan’s success.
France’s Offensive Doctrine: The Spirit of Attack
Meanwhile, in France, the outbreak of war was viewed as an opportunity to settle long-standing grievances with Germany. Rather than adopting a defensive posture, French Commander-in-Chief Joseph Joffre formulated an aggressive plan of his own, centered on the concept of the “offensive à outrance.”
Joffre’s strategy involved a two-pronged attack: a “right jab” into Lorraine, intended to signal French commitment to the alliance with Russia, followed by a decisive “left hook” through Belgium, aimed at delivering a knockout blow to Germany.
Hammond explains the prevailing French military philosophy: “The French soldier was reckoned to be keen, fiery and full of initiative. Everything had to be done to create an ‘offensive spirit’ to carry the attacking men forward. With this thinking predominant in the French Army, everything was seen through the ‘spirit of offensive’ lens. Anything not ‘offensive’ enough was opposed. It was widely believed that the end of any future conflict with Germany would come in one huge battle, likely to be costly in human life, but decisive.” This unwavering belief in the offensive, however, would prove tragically out of sync with the realities of modern warfare.
Initial German Advances and Unexpected Resistance
On August 4th, 1914, German forces launched their offensive. While a limited number of army corps were positioned to defend the border with France, the main thrust of the German army surged into Belgium, triggering Britain’s entry into the war the following day. The Schlieffen Plan hinged on speed, prompting the Germans to commit their reserve forces with the 1st and 2nd Armies on the right flank from the outset.
The next day, German troops reached Liège, a strategically vital fortress city and railway hub. Capturing Liège was crucial for ensuring the swift flow of German supplies. However, the city’s forts, though eventually subdued by super-heavy artillery, offered unexpectedly stiff resistance, causing a significant delay in the German advance. By this time, French forces had mobilized and were poised to launch their own offensives.
Hammond points out a crucial detail regarding French uniforms: “It’s a common misunderstanding that the French deliberately and consciously went to war in 1914 with soldiers wearing the classic dark blue coat and red trousers, the pantalon Garance, that feature here in IWM’s First World War galleries. But in fact in July 1914, France had decided to adopt the horizon bleu that would eventually replace this traditional uniform. However, it was all too late. The speed with which the European crisis developed meant that France embarked on a modern industrial war of unprecedented scale in uniforms from the previous century.” This detail highlights the rapid pace of events and the French army’s unpreparedness in some aspects despite their offensive doctrine.
Throughout August, three French armies launched a series of attacks across the border into Germany as part of Joffre’s “right jab,” while other forces moved into Belgium to execute the “left hook.” However, these assaults were decisively repulsed within days, resulting in catastrophic losses for the French.
Hammond elaborates on the disastrous French tactics: “In their attacks, there was little co-ordination between artillery and infantry. The direct support of the otherwise-excellent French 75s wasn’t to the conditions of modern warfare actually encountered. Much thinking before the war had been based on the focus on infantry combat as exchanges of rifle fire, supported by direct fire from these guns. But they failed to take consideration of, or even mention the machine-gun. The losses the French suffered were appalling. On 22nd August 1914 alone, 21,035 French soldiers died. The tactics of the 19th century were utterly futile in the face of the weapons of modern industrial warfare.” The French commitment to outdated offensive tactics in the face of modern weaponry contributed significantly to their early setbacks.
Simultaneously, in Belgium, German forces continued their advance but encountered far more resistance than anticipated. Belgian forces fought with tenacity, bravely demolishing bridges and railways, hindering the German progress. Frustration over these delays fueled aggressive actions by German troops against Belgian civilians, escalating into acts of brutality.
Hammond sheds light on the dark side of the German advance: “The German fears of civilian resistance were almost wholly baseless, but what they believed were atrocities against their own men became a self-fuelling myth. Their reaction as they continued advancing through Belgium saw more and more civilian massacres. From August to October 1914 the German Army intentionally executed 5,521 civilians in Belgium and 906 in France – acts seized on for propaganda purposes by the French and British.” These atrocities, while strategically counterproductive, became potent propaganda tools for the Allied powers.
The Great Retreat and the Turning Tide at the Marne
In late August, the German 1st and 2nd Armies clashed with French and British forces at the battles of Charleroi and Mons. The British Expeditionary Force (BEF), a highly professional army, was significantly outnumbered by the advancing Germans. After initially repelling a German attack, the arrival of German heavy artillery forced the British to retreat. The Allied forces then commenced a prolonged withdrawal into France, known as the Great Retreat. The German advance appeared unstoppable. However, the tide was about to turn.
In the East, Russian mobilization proceeded at a much faster pace than German planners had anticipated. Instead of the expected six weeks, two Russian armies invaded Germany just 15 days after mobilization began. On August 25th, Moltke, under pressure, dispatched two army corps from the Western Front to reinforce the Eastern defenses. Before these reinforcements arrived, German forces achieved a stunning victory at the Battle of Tannenberg, temporarily alleviating the Russian threat. However, these two corps would be sorely missed in the critical battles to come in France. As German strength waned, the French army began to reorganize and regain its footing.
Hammond highlights Joffre’s leadership during this critical period: “It was now that Joffre showed his qualities as a leader and a period of savage discipline began in the French Army that lasted until 1915. Those even suspected of cowardice were sometimes summarily shot without proper trial by senior commanders, while Joffre took an axe to the existing corps of senior officers and sacked, demoted or transferred any he felt were inadequate. A disastrous situation had been brought under control and now France stood ready to take the offensive again.” Joffre’s ruthless reforms and reorganization were crucial in revitalizing the French army.
By mid-September, the Allied retreat culminated in defensive lines behind the River Marne. Joffre strategically redeployed troops to Paris via the French railway network, forming a new Sixth Army to defend the capital. As the Germans approached Paris, they began to encounter logistical and communication problems. A lack of clear communication between the field armies and Moltke’s high command hampered coordination. This communication breakdown led General von Kluck, commanding the German 1st Army on the crucial right flank, to deviate from the Schlieffen Plan.
Instead of adhering to the plan’s objective of encircling Paris, von Kluck opted to pursue and decisively defeat the retreating French forces before they could regroup. Von Kluck, believing he was on the verge of a historic victory, made a fateful decision that would ultimately be remembered for all the wrong reasons. French commander Joffre, anticipating an opportunity to counterattack, recognized von Kluck’s exposed position and formulated a plan to halt the German advance decisively. The stage was set for a titanic clash along the River Marne.
Joffre’s counteroffensive plan centered on attacking the exposed right flank of the German forces. The French 6th Army would attack from the west, the BEF from the southwest, and the French 5th Army from the south. The remaining French forces would maintain pressure on the German forces along the front.
On September 5th, the French 6th Army launched its attack, catching von Kluck’s 1st Army completely by surprise. German cavalry reconnaissance had proven ineffective, leaving them largely unaware of Allied positions. The French attack struck German troops who had been marching and fighting for over 30 days, operating far beyond their supply lines and suffering from fatigue and attrition.
Hammond details the weakened state of the German 1st Army: “In the German 1st Army the combat units were severely impacted by losses of around 50% through battle, fatigue, hunger and exhaustion. Their heavy artillery lagged far behind the main advance and the lead troops were operating far from places where supplies were being delivered by rail. All these factors ensured they did not have the force strength to add momentum at the critical time.” The cumulative effects of fatigue, losses, and logistical strains significantly weakened the German 1st Army at the decisive moment.
Faced with the French counterattack, Von Kluck redeployed his army westward to meet the threat head-on. However, this maneuver created a 30-mile gap between his 1st Army and Von Bülow’s 2nd Army. The following day, the BEF and the French 5th Army exploited this gap, slowly but surely establishing a bridgehead across the Marne, threatening to isolate von Kluck’s forces. The Battle of the Marne was a massive and sprawling engagement, stretching from Paris to Nancy, involving over two million soldiers.
On September 7th, von Kluck’s 1st Army counterattacked towards Paris, but French reinforcements, famously transported by Parisian taxicabs, held the line. Meanwhile, the most perilous moment for the Allies occurred at the Marshes of St. Gond, where the German 2nd Army nearly breached the French lines. However, the widening gap between the German armies and the relentless pressure from British forces made it increasingly clear that the Germans would have to retreat. The Battle of the Marne concluded with a decisive Allied victory, and the Schlieffen Plan lay in ruins.
By September 13th, German forces had retreated to defensive positions behind the River Aisne. There, they began digging the first trenches of the war. While the Germans had seized valuable economic territories and occupied significant portions of Northern France and Belgium, they now faced the very scenario the Schlieffen Plan was designed to prevent: a protracted two-front war, compounded by a naval blockade imposed by the Royal Navy.
Hammond concludes, “Meanwhile, France’s offensive obsession was far from over. Propelled now by a patriotic fervour to drive the invader from the nation’s sacred soil, the French Army’s offensives of late 1914 and 1915 would continue to result in barely sustainable manpower losses and a drain on the lifeblood of the nation. Germany’s short war gamble had failed. A new kind of war – total war – had begun.” The failure of the Schlieffen Plan ushered in a new era of warfare – a brutal and protracted conflict characterized by trench warfare and unprecedented levels of industrialized violence.
The Key Reasons for the Schlieffen Plan’s Failure
In summary, the Schlieffen Plan failed due to a confluence of factors:
- Underestimation of Belgian Resistance: Belgian forces, though smaller, offered unexpectedly tenacious resistance, slowing the German advance and disrupting the crucial timetable.
- Faster than Expected Russian Mobilization: Russia’s rapid mobilization forced Germany to divert troops from the crucial Western Front, weakening the Schlieffen Plan’s right flank.
- Modifications by Moltke: Moltke’s alterations to the original Schlieffen Plan, intended to reduce risk, diluted the offensive power of the critical right wing, reducing its ability to achieve a decisive encirclement.
- Logistical Challenges and Fatigue: The rapid German advance outstripped supply lines, leading to fatigue, exhaustion, and shortages of supplies for front-line troops, particularly in the critical 1st Army.
- Communication Breakdown and Misjudgment by von Kluck: Poor communication within the German command structure and von Kluck’s decision to deviate from the encirclement plan to pursue the French created a critical gap in the German lines, exploited by the Allies at the Marne.
- French Resilience and Joffre’s Leadership: Despite initial setbacks, the French army, under Joffre’s decisive leadership, demonstrated resilience, reorganized effectively, and launched a successful counteroffensive at the Marne.
- The “Spirit of Offensive” Backfired: While intended to inspire, the French “offensive à outrance” doctrine led to disastrously costly and ineffective attacks in the face of modern firepower, weakening their forces early in the campaign.
Ultimately, the Schlieffen Plan, while initially promising, was undone by a combination of unforeseen resistance, strategic miscalculations, logistical shortcomings, and the unexpected resilience of the Allied forces. Its failure marked the end of hopes for a short war and plunged Europe into the protracted and devastating conflict of World War I.
