¹ Rodin, David, War and Self-Defense (New York: Oxford University Press, 2003Google Scholar). All in-text citation references are to this book.

² The operation of reciprocity is apparent also in other elements of the right; for example, in the notion of proportionality. Though it appears at first sight to be a form of consequentialist requirement, proportionality does not in fact require us to balance the overall harms and benefits of an act of defense, for an innocent defender is entitled to kill literally any number of culpable attackers. On the contrary, proportionality requires us to balance the harm inflicted upon a particular person, against the harm with which he threatens us. Proportionality in self-defense is therefore best regarded as deriving from a kind of interpersonal moral reciprocityGoogle Scholar.

³ Understanding which innocent threats and innocent aggressors one may properly harm in self-defense requires a detailed examination of the theory of excuseGoogle Scholar.

⁴ This may provide grounds for rehabilitating the idea of military force as a form of law enforcement or even punishment, though careful attention must be paid to the idea of authority: in most cases states at war will lack the authority required for proper punishment or law enforcementGoogle Scholar.