Thu Feb 24, 2011
Howison Library, 4:10–6 PM
Jeff McMahan (Rutgers)
Proportionality in Self-Defense and War
Proportionality is a familiar constraint on acts that cause harm, such as punishment, self-defense, and acts of war, yet it has hitherto been poorly understood. I will explore a range of unappreciated complexities in the notion of proportionality, particularly in its application to self-defense and war. I will begin by distinguishing between two independent proportionality requirements, one governing harms to those who are potentially liable to be harmed and another governing harms to those who are innocent, or not liable. This distinction enables us to understand better what is at issue in certain questions that have been posed only recently. For example, among the many good and bad effects that an act may have, which count in proportionality judgments? Among those that count, do some have different weights because of differences in the way in which they were brought about? What kind of comparison is required in judging whether an act is proportionate and what is the appropriate baseline for the comparison? Can those who fight in a war that lacks a just cause satisfy any of the relevant proportionality requirements, even in principle? If not, what are the implications for the law of war, which seeks to impose effective constraints even on those who fight in unjust wars?