On 4 March, General Louis Franchet d'Espèrey, commander of Groupe d'armées du Nord (GAN: northern army group), advocated an attack, while the Germans were preparing to retreat. About 125,000 able-bodied French civilians in the region, were transported to work elsewhere in occupied France, while children, mothers and the elderly were left behind with minimal rations. Railways and roads were dug up, trees were felled, water wells were polluted, towns and villages were destroyed and a large number of mines and other booby-traps were planted. The operation began on 9 February 1917 throughout the area to be abandoned. Rupprecht was appalled by the scale and methods proposed for a scorched earth policy and contemplated resignation, then concluded that it might suggest a rift had developed between Bavaria and the rest of Germany. The order for the withdrawal to begin was issued on 16 March. A move back to the Hindenburg Line ( Siegfried Stellung) would shorten the front by 40–45 kilometres (25–28 mi) and require 13 fewer divisions. Other options, such as a shorter withdrawal were also canvassed but lack of manpower made the decision inevitable, since even with reinforcements from the Eastern Front, the German army in the west numbered only 154 divisions against 190 Allied, many of which were larger. Ludendorff accepted the plan after representations by Rupprecht, Crown Prince of Bavaria, commander of Army Group Rupprecht (1st, 2nd, 6th and 7th armies, from the Somme front to the North Sea coast) over the objections of the 1st and 2nd Army commanders. A study suggested that seventeen divisions might be made available but that this was far too few for a decisive effect in the west.

An offensive was considered if enough reserves could be assembled in the new year. Ludendorff was unsure as to whether retreating to the Siegfriedstellung ( Hindenburg Line) was the best thing to do, since withdrawing might diminish the morale of German soldiers and civilians. Soon after taking over from Erich von Falkenhayn as Chief of the General Staff in at the end of August 1916, Paul von Hindenburg and Erich Ludendorff, First Erster Generalquartiermeister ordered the building of a new defensive line, east of the Somme battlefront from Arras to Laon. The British referred to it as the German Retreat to the Hindenburg Line but the operation was a strategic withdrawal rather than a retreat. It was a planned withdrawal to new positions on the shorter, more easily defended Hindenburg Line ( Siegfriedstellung), which took place between 9 February and 20 March 1917 and eliminated the two salients which had been formed in 1916, between Arras and Saint-Quentin and from Saint-Quentin to Noyon, during the Battle of the Somme. Operation Alberich ( Unternehmen Alberich) was the codename of a German Army military operation in France during World War I.

Tannenberg battle coordinates