Schlieffen Plan

The Schlieffen Plan is the name given to Germany’s plan for a two-front war, with which it entered the war in August 1914. It assumed that the army would first defeat France quickly, outflanking its fortified frontier through Belgium, and only then turn against Russia, which mobilised more slowly. In 1914 it was carried out in a version reworked by Schlieffen’s successor, which is why some historians prefer to speak of the Moltke Plan.

Schlieffen’s concept

Ever since the Franco-Russian alliance, German staff officers had been preparing for a war against two enemies at once. Alfred von Schlieffen, Chief of the General Staff from 1891, set down his answer in December 1905, in a memorandum written just before his retirement. Russia, just beaten by Japan and shaken by revolution, looked weak at the time. In the east the army was at first to stay on the defensive, while its main strength struck quickly at France.

Schlieffen meant to bypass the belt of fortresses from Verdun to Belfort from the north. A very strong right wing was to pass through Luxembourg, Belgium and the Netherlands, swing round in a great arc, go round Paris on the west side too and trap the French armies in an encirclement. The General Staff regarded the violation of three states’ neutrality as of little consequence.

Moltke’s changes

Schlieffen’s successor, Helmuth von Moltke, reworked the plan over the following years. He dropped the march through the Netherlands to keep it as a neutral window for German trade, but in return the right wing had to pass through a narrow corridor and take the fortress of Liège in the first days of the war. He also strengthened the armies in Alsace and Lorraine at the expense of the right wing. In 1913 work on a separate plan for a war against Russia alone was abandoned, so from then on any war with Russia meant an immediate attack on France through Belgium. In July 1914 this rigidity narrowed the room for diplomacy, and the invasion of Belgium brought Britain into the war.

August and September 1914

In the west Germany deployed seven armies, in the east one. After the fall of Liège the Germans crossed Belgium and won the Battle of the Frontiers, but the plan began to fail. The Russians entered East Prussia sooner than expected and at Gumbinnen repulsed an attack by the German 8th Army. On 25 August Moltke decided to send two corps from the right wing to the east. They arrived only after the Battle of Tannenberg and were missing on the Marne. Further forces had to be left at Maubeuge and Antwerp.

At the end of August Alexander von Kluck, commander of the 1st Army on the far right, turned south-east in pursuit of the French and led his troops east of Paris rather than west of it. On 6 September the French and British struck his exposed flank in the Battle of the Marne, and on 9 September the German right-wing armies began to retreat. On 14 September Erich von Falkenhayn took over command from Moltke. The quick victory was lost, and Germany was condemned to a long war on two fronts.

The historians’ debate

After the war former staff officers, among them Wilhelm Groener, presented Schlieffen’s memorandum as a recipe for victory squandered by the irresolute Moltke. The text itself was made public only after the Second World War by the historian Gerhard Ritter. In the early 21st century the American Terence Zuber argued that the memorandum was not a war plan and that there had never been a Schlieffen Plan at all. He did not convince most scholars, but the debate was a reminder that there had never been a sure recipe for victory, and that the plan carried out in 1914 was Moltke’s responsibility.