In March 1917, leaders of the German Army on the Western Front decided to withdraw from their positions in France to the Hindenburg Line, a 90-mile long defensive position that ran from Arras to Laffaux. With Germany unable to conduct an offensive because of personnel losses earlier in the war, commanders intended for unrestricted submarine warfare and strategic bombing to weaken the British and French, giving the German army time to recuperate. In addition, the move to the Hindenburg Line supported the plan of commanders Paul von Hindenburg and Erich Ludendorff to shift the German focus to Russia and the Eastern Front. The withdrawal to the new defensive line would shorten Germany's front by 25 miles, enabling 13 divisions to be employed against the Russians.