Despite his differences with Stauffenberg, Goerdeler appreciated Stauffenberg for solving a problem that had bedevilled him since 1938. Goerdeler had always assumed that to stage a "putsch" required recruiting a senior military figure who could order large bodies of troops into action against the Nazi regime, and it had been the unwillingness of senior military officers to be recruited like Kluge, who could never quite make up his mind, or Halder, who had severed relations with Goerdeler in 1940 once he became convinced that Hitler would win the war that had prevented him from staging a "putsch". Stauffenberg solved that problem by devising Operation Valkyrie, a plan that ostensibly was meant to crush a slave labour uprising but really was the cover for a "putsch" that could be activated by officers of less than senior rank. Goerdeler was pleased that at long last, the means for a "putsch", without the senior officers who were plainly not willing to break with the regime, had been devised by Stauffenberg, but his uneasy relations with Stauffenberg were described by the German historian Hans Mommsen as one of mutual "misunderstandings".