The Schlieffen plan was a plan created by Alfred Von Schlieffen, aimed to capture Paris and defeat France within the first few days of a war solving the problem of the two fronted war. The plan involved sweeping through neutral Belgium and Holland with little resistance, then sweeping South West through France to Paris. There, the German army would encircle Paris from behind, split up its divisions and surround the capital of France; then the Germans would capture the city or France would surrender. This plan was aimed to last for 5 weeks, by that time the Russian army would...
Belgium, the rapid deployment of the BEF surprised Germany. Germany faced many problems of supply and communication as they moved closer to Paris, Germany underestimated Belgium resistance, Germany underestimated speed of Russian mobilization, and Germany under estimated reaction of Great Britain to violation of Neutrality Treaty. Overall all these factors added up to the failure of one of the most ambitious war plans ever created. I believe that the intervention of the British Expeditionary Force was a great factor as they slowed the Germans greatly; however, I believe the key factor was Von Moltke loosing his nerve and retreating.