Stieff joined the Wehrmacht General Staff in 1938, serving in the " Organisationsabteilung " ( coordination department ) under Major Adolf Heusinger.
Prior to signing the declaration and discussing it with the press, Eisenhower met with former Wehrmacht generals Adolf Heusinger and Hans Speidel, both participants in the Himmerod conference, and was impressed by them.
Discussions proceeded on March 17 during a situation conference, where Chief of the OKH General Staff Franz Halder, Quartermaster-General Eduard Wagner and Chief of Operational Department of the OKH Adolf Heusinger were present.
Many former German officers, including Adolf Heusinger and Hans Speidel, who had served on Rommel's staff in France, were convinced that no future West German Army would be possible without the rehabilitation of the Wehrmacht.
In the watershed year of 1942, according to Gehlen's memoir, he was approached by Colonel Henning von Tresckow, Colonel Claus von Stauffenberg and General Adolf Heusinger to participate in an assassination attempt on German head of state Adolf Hitler.
Tresckow also applied to become General Adolf Heusinger's delegate in the Army High Command ( OKH ) during the latter's two-month leave, which would also give him access to Hitler's meetings, but Heusinger, who was earlier approached by conspirators, rejected it apparently for the same reason.