To what extent the failure of the plot and the brutal response against those involved in it affected Mattenklott's stance towards the evergrowing denialism showed by Hitler in view of Germany's impending defeat is not known. But as the Western Allies made their push in western Germany in the spring of 1945, Mattenklott followed the unrealistic orders of his superiors. By then, Mattenklott was leading the Wehrkreis units in a desperate defence of the area around Paderborn in North Rhine-Westphalia. On 1 April 1945 he reported to his superior, the Supreme Commander West (Oberbefehlshaber West), Generalfeldmarschall Albert Kesselring, that Paderborn was lost to the enemy after it was defended to the last man; he was committed in holding the Teutoburg Forest, but warned he was not able to deploy any significant forces.