In 1956, the English historian J. F. C. Fuller called the military operations on the Meuse in 1940, "the Second Battle of Sedan". Fuller called the German operation an "attack by paralyzation" but Robert Doughty wrote that what some writers later called blitzkrieg had influenced few German officers, except for Guderian and Manstein and that the dispute between Guderian and Kleist that led Guderian to resign on 17 May, showed the apprehensions of the higher commanders about the "pace and vulnerability" of the XIX Panzer Corps. Doughty wrote that the development of the German plan suggested that sending armoured forces through the Ardennes was traditional "Vernichtungsstrategie" (strategy of annihilation), to encircle opposing forces and destroy them in a "Kesselschlacht" (cauldron battle). Weapons had changed but the methods were the same as those at Ulm (1805), Sedan (1870) and Tannenberg (1914).