Beck resented Hitler for his efforts to curb the army's position of influence. Though he was hardly a pacifist, he opposed wars of conquest and only supported ideological war, when he believed that the military was fully prepared for it. As such, he opposed the takeover of Czechoslovakia and made every effort to thwart Hitler's plans. Finally, when he realized that this would be impossible, he resigned in protest.
Beck lived in retirement until 1944, when he was asked by the conspirators in the failed assassination plot to take over as leader of Germany once Hitler was dead. When the plot failed, Beck committed suicide rather than suffer torture and execution. According to the story, he was so shaken up, that two bullets that he attempted to shoot into his brain missed, so that he finally had to ask a sergeant to help him finish the job.