An electrically operated surgical instrument (1) comprises a handle (10) having a power supply (600), a drive assembly (200), and a control assembly (618, 620). A surgical end effector is connected to the handle (10) and has a pair of opposing compression surfaces (50, 60) applying a compressive force to tissue therebetween, and a tissue-cutting assembly comprising a blade (1060) connected to a drive part (232, 240, 250, 260, 270, 290, 300, 320) of the drive assembly (200). The control assembly (618, 620) selectively causes a motor (210, 212) of the drive assembly (200) to automatically retreat the drive part to place the blade (1060) in a retracted position of the blade.
