The Schlieffen Plan was created by General Count Alfred von Schlieffen in December 1905. The Schlieffen Plan was the operational plan for a designated attack on France once Russia, in response to international tension, had started to mobilise her forces near the German border. The execution of the Schlieffen Plan led to Britain declaring war on Germany on August 4th, 1914.
In 1905, Schlieffen was chief of the German General Staff. Europe had effectively divided into two camps by this year - Germany, Austria and Italy (the Triple Alliance) on one side and Britain, France and Russia (the Triple Entente) on the other.
Schlieffen believed that the most decisive area for any future war in Europe would be in the western sector. Here, Schlieffen identified France as Germany's most dangerous opponent. Russia was not as advanced as France in many areas and Schlieffen believed that Russia would take six weeks to mobilise her forces and that any possible fighting on the Russian-German border could be coped with by the Germans for a few weeks while the bulk of her forces concentrated on defeating France.
Schlieffen concluded that a massive and successful surprise attack against France would be enough to put off Britain becoming involved in a continental war. This would allow Germany time (the six weeks that Schlieffen had built into his plan) to transfer soldiers who had been fighting in the successful French campaign to Russia to take on the Russians.
Schlieffen also planned for the attack on France to go through Belgium and Luxemburg. Belgium had had her neutrality guaranteed by Britain in 1839 - so his strategy for success depended on Britain not supporting Belgium.
The Schlieffen Plan was revised as tension in Europe increased. However, the basic mechanics of it remained the same:
a devastating attack on France via Belgium as soon as Russia had announced her intention to mobilise.
a holding operation on the Russian/German border to be carried out if necessary and if required.
Germany had 6 weeks to defeat France.
Germany would then use her modernised rail system to move troops from the French operation to the Russian front.
Russia would then be attacked and defeated.
The Schlieffen Plan was daring but it had a number of glaring weaknesses:
The actions of Russia determined when Germany would have to start her attack on France even if she was ready or not.
It assumed that Russia would need six weeks to mobilise.
It assumed that Germany would defeat France in less than six weeks.
In fact, the attack in August 1914 nearly succeeded and was only defeated by the first Battle of the Marne. Poor communication between the frontline commanders and the army's headquarters in Berlin did not help Moltke's control of the campaign. Also the withdrawal of German troops in response to a higher than expected threat on the Russian front, meant that the Germans did not have the military clout that Schlieffen had built into his original plan. It was a plan that nearly succeeded but its success could only be measured by being 100% successful. France had to be defeated - and this did not happen. Schlieffen's speedy attack and expected defeat of France never occurred - it's failure did usher in the era of trench warfare that is so much linked to World War One.