The plan was to invade France through neutral Belgium, avoiding the majority of the French army that was stationed on the border with Germany. They would race past the French troops and capture Paris within six weeks. Once Paris had been seized, the rest of France would fall, and they could then turn to face the Russians.
The Germans did not in the slightest fear the British army, which the Kaiser described as “contemptibly small”. In actual fact they did not even expect them to enter the war. British Prime Minister Lord Palmerston signed a covenant in 1839 promising to defend Belgium should they be invaded. It was called the ‘Treaty of London’. The Kaiser insisted that they wouldn’t be dragged into a war over what he called “a scrap of paper”, after all, it was signed over 70 years ago. Schlieffen, however, wanting to cover every possible eventuality, planned to capture the main ports on the Channel; Ostend, Dunkirk, Calais and Boulogne, as they swept south, thus preventing the British Expeditionary Force from getting across in large numbers.
The plan was based on many assumptions, one of which was that Russia would be slow to mobilise its army, and would take longer than six weeks, by which time they would hopefully have captured France. They believed this because they knew that Russia was a very large country, and that their communications were fairly poor. Another assumption that the plan hinged on was Belgium’s small army not providing much resistance, so they could march through to France quickly.
However it became clear by August 1914 that the Schlieffen plan was outdated, and was based on too many assumptions to be successful.
