 Complete the following phrase:  With regard to a possible future two-front war, Alfred von Schlieffen, the Chief of the General Staff from 18911906, had suggested a deployment scheme which became known as the Schlieffen Plan. Modified by Moltke the Younger, its intention of quickly defeating France proved impossible to achieve. In the actual event of the first world war; on the Western Front, the German advance stalled into trench warfare after the First Battle of the Marne. On the Eastern Front, however, the Prussian operations succeeded in encircling and smashing the Russians at 