The Schlieffen Plan was created in 1905 by Count Alfred von Schlieffen to ensure German victory over France and Russia in a potential war. The plan aimed to knock France out quickly by attacking Paris with an overwhelming force of 90% of the German army within six weeks, while defending against Russia with the remaining 10%. However, the plan failed because Schlieffen underestimated the Russian army and how quickly it could mobilize, and there were not enough German troops left on the borders to hold back the Russian advance.