The true reason for the decision to halt the German armour on 24 May is still debated. One theory is that Von Rundstedt and Hitler agreed to conserve the armour for "Fall Rot" ("Case Red"), an operation to the south. It is possible that the Luftwaffe's closer ties than the army's to the Nazi Party contributed to Hitler's approval of Göring's request. Another theory—which few historians have given credence—is that Hitler was still trying to establish diplomatic peace with Britain before Operation Barbarossa (the invasion of the Soviet Union). Although von Rundstedt after the war stated his suspicions that Hitler wanted "to help the British", based on alleged praise of the British Empire during a visit to his headquarters, little evidence that Hitler wanted to let the Allies escape exists apart from a self-exculpatory statement by Hitler himself in 1945. The historian Brian Bond wrote: