In serving as Chief of Staff of the German Army between 1935 and 1938, Beck became increasingly disillusioned and stood in opposition to the increasing totalitarianism of the Nazi regime and to Hitler's aggressive foreign policy. Public foreign-policy disagreements with Hitler made Beck resign as Chief of Staff in August 1938. From then on, Beck came to believe that Hitler could not be influenced positively and that both Hitler and the Nazi Party had to be removed from government. Beck became a major leader within the conspiracy against Hitler and would have served as head of state with the title of either President or regent ("Reichsverweser"), depending on the source, if the 20 July plot had succeeded. The plot failed, however, and Beck was then arrested. He reportedly made an unsuccessful attempt at suicide before he was shot dead.