This chapter differentiates technologies aiming at restoring individuals’ physical or psychological faculties from those aiming at increasing them. While the former type of technology finds its moral justification in sound arguments, the latter are seen by many as being more questionable. This chapter discusses the fear associated with capacity-increasing technologies in the military sphere, particularly with regard to the risk of creating an asymmetry between combatants. Despite the fact that the moral reasons for the use of capacity-restoring technologies are very different from those of capacity-increasing technologies, it would nonetheless be a mistake to automatically condemn the latter. Of course, they create an asymmetrical relationship between the states that have them and the ones who do not; however, this inequality between combatants does not challenge the moral justification for killing during wartime. Indeed, capacity-increasing technologies allow some soldiers to augment their chances of survival on the battlefield, but they do not create a situation where their beneficiaries will become absolutely invulnerable to being wounded or killed. Based upon the morality of warfare, this distinction, is not insignificant, as it is the core element that allows individuals to kill other human beings in times of war. Therefore, as long as these technologies will not engender invulnerability, they should not be considered as morally reprehensible.