This essay analyzes the use of military robots in terms of the jus in bello concepts of discrimination and proportionality. It argues that while robots may make mistakes, they do not suffer from most of the impairments that interfere with human judgment on the battlefield. Although robots are imperfect weapons, they can exercise as much restraint as human soldiers, if not more. Robots can be used in a way that is consistent with just war theory when they are programmed to avoid using force against all but the most clearly hostile targets. However, the essay also cautions against using robots for counterinsurgency because they may alienate people in the contested area and lead to an escalation of hostilities.