Strategic discussions also occurred on the German side, with Field Marshal Erich von Manstein arguing for a mobile defence that would give up terrain and allow the Soviet units to advance, while the German forces launched a series of sharp counterattacks against their flanks to inflict heavy attrition. But for political reasons, German Chancellor Adolf Hitler insisted that the German forces go on the offensive, choosing the Kursk salient for the attack.[33] On 15 April 1943 he authorised preparations for Unternehmen Zitadelle (Operation Citadel).[34]