They believed Britain would go to war over Hitler's planned invasion of Czechoslovakia, and Germany would lose. The plan was to overthrow Hitler or possibly assassinate him. Participants included Generaloberst Ludwig Beck, Generaloberst Walther von Brauchitsch, Generaloberst Franz Halder, Admiral Wilhelm Canaris, and Generalleutnant Erwin von Witzleben, who joined a conspiracy headed by Oberstleutnant Hans Oster and Major Helmuth Groscurth of the Abwehr.