Devised by the German Chief of Staff Alfred von Schlieffen, the Schlieffen Plan was the German early 20th century strategic plan for a two-front war in Europe, on the Western Front against France and on the Eastern Front against Russian Army, taking advantage of expected differences in the three countries’ speed in preparing for war. In modified form, it was executed to near victory in the first month of World War I. But the modifications to the original plan, a French counterattack, and speedy Russian offensives, ended the German offensive and resulted in years of trench warfare.
The Schlieffen Plan strategy was to win a two-front war by quickly beating France first in the west, as had been done before in the Franco-Russian War of 1870-1871, then concentrate all the military resources to defeat Russia in the east. To win a fast victory over France, the Schlieffen Plan involved a Germany invasion of Belgium and a right-wing flanking movement through Holland and then southwards, to cut off Paris from the sea; a scythe-like sweeping attack through these countries to surround Paris.