Schlieffen Plan

You are a decorated Field Marshall and a German war hero and you always expected that Germany might have to wage a war with both Russia and France, but you don't want to split your armies in two. So you devise a plan to defeat France as quickly and decisively as possible so that you can go back and deal with the Russians to the east. This was the Schlieffen plan.

Schlieffen Plan Definition WW1

The Schlieffen Plan war plan devised by the Prussian Field Marshall, German war hero and former chief of the German General Staff, Alfred von Schlieffen, between 1905 and 1906. According to Schlieffen, if Germany was to have to fight on two fronts, against Russia in the east and France to the west, it would have to launch a preemptive strike to win.

The preemptive strike would be launched against France first and avoid fighting on the Franco-German border. Instead, the Schlieffen plan envisioned attacking France through Belgium, defeating France by taking Paris, and only then turning back to fight the Russians to the east.

Fig. 1: Alfred von Schlieffen, 1906

Schlieffen Plan WW1

The Schlieffen Plan came into existence in 1906, at a time when Germany began fearing the possibility of a two-front war with both Russia and France. To come out victorious in this scenario, Schlieffen devised a strategic plan that could help Germany avoid fighting two enemies on two separate fronts.

Schlieffen's plan in theory was simple: cross into Belgium, invade France, take Paris, march east and defeat the Russians there. Schlieffen was confident in the abilities of the German military and why wouldn't he be? This was the same military forged by the great Otto von Bismarck, under whose leadership Germany had become the most feared power in Europe.

On 28 July 1914, the Archduke of Austria, Franz Ferdinand was assassinated while on his trip to Sarajevo. This kicked off the First World War, whose first battle was not fought until September.

When the war began, Schlieffen was long retired. In his place, the Chief of the German General Staff, the head of the German army, was Helmuth von Moltke. Moltke was sympathetic to Schlieffen's plan and used it to try to invade France.

What followed, however, was an utter failure. Moltke's execution of the Schlieffen Plan was a severe miscalculation. Germany never defeated France and the Russians attacked from the east. Schlieffen's fears of Germany having to fight on two fronts came true.

Failure of the Schlieffen Plan

The Schlieffen Plan failed because of German miscalculation and overconfidence.

As tensions built throughout July, Germany prepared to execute the Schlieffen Plan and cross into Belgium to invade France. In the main section of the Schlieffen Plan, the invasion and swift defeat of France were to last no more than six weeks. Why six weeks? Because that is how long the Germans believed it would take the Russians to mobilise their armies on the Russo-German border.

The German plan was to defeat the French and swiftly move east to face the incoming Russian armies. Moltke and the entire German war effort were about to face their greatest fear, fighting on two fronts, very soon.

Fig. 2: The original Schlieffen Plan

Germany was confident that Belgium would not dare to challenge the German army. On 2 August, Germany demanded that its army was to be given free passage through Belgium, only for the Belgian government to refuse on 3 August. German soldiers entered Belgium by force but were met with resistance.

This was unexpected from the Belgians, they had attempted armed resistance against Germany. The British, as guarantors of Belgian independence, declared war on Germany when the 1839 Treaty of London was invoked.

Fig. 3: Moltke's execution of the Schlieffen Plan

The attack on Belgium demonstrated that Germany was not the only one with a war plan. France had activated Plan XVII with which they were able to mobilise their armies and prepare for war.

Among the failures of the Schlieffen Plan, the unexpected resistance from Belgium was among the top reasons why the German tactic failed. The Belgians, with French support, stalled the Germans long enough for the Russians to fully mobilise. Russian mobilisation, in itself, was the single greatest miscalculation the Germans had made.

It turned out that the six-week period, which was the time the Germans estimated it would take for the Russian armies to mobilise was completely false. The Russians were at Germany's border in only 10 days.

The German army successfully defeated the Belgian and French forces but it was becoming obvious that the Russians had already mobilised. Moltke, believing that crossing Belgium would be much easier, had sent fewer soldiers than the Schlieffen Plan had originally required. This weakened the German offensive and slowed their progress.

With the Russians invading from the east, Moltke was forced to detach 100,000 soldiers to the east to fight them. This further weakened the German advance into France.

The Schlieffen Plan had officially failed. In turn, the commander of the Western armies, who had already infiltrated France, general Alexander von Kluck, tried to outflank the French and the recently arrived British forces but was severely defeated in the First Battle of the Marne. Germany was officially fighting on two fronts, the very thing that the Schlieffen Plan had been designed to prevent.

Schlieffen Plan Significance

The Schlieffen Plan lies demonstrated German hubris. Moltke's execution of the Schlieffen Plan was a deviation from the original. He believed that crossing Belgium would be effortless and that defeating France was certain and he allocated fewer soldiers to execute the Schlieffen plan than it required.

Fig. 4: Mobilisation order is read out in Berlin, preparing the public for the Schlieffen Plan

German hubris reared its head again leading up to the Second World War. Adolf Hitler frequently criticised the commanders of the German war effort for their ineptitude and subsequent surrender. He vouched that this time, things would go differently. And it did, for a time.

Hitler managed to occupy not only France but Belgium, the Netherlands, and Luxembourg in exactly six weeks. Hitler's decision in 1941 to invade the Soviet Union opened a front in the east and was ultimately a key factor in Germany's downfall.

The Schlieffen Plan is a great example of German military hubris in the 20th century. The plan completely underestimated the abilities of other countries while unrealistically exaggerating its own.

Fig. 5: Moltke and the war plan of the First Battle of the Marne