[Note from Kathie Malley-Morrison: Today we once again welcome guest contributor Dr. Michael Corgan, for his ongoing series on just war.]
The idea of proportionality is one of the more comprehensive notions in both the international laws governing war and in just war theory. Proportionality applies both to the resort to war and the conduct of a war, however justly or legally entered into.
In terms of international law, the only just or legal cause for war is self-defense against aggression. But the UN Charter in particular countenances not just the repulsion of aggression and punishment for its having been used. In just war theory, proportionality places no such requirements on those repelling aggression. War can stop or undo the harm but not be an excuse for vengeance or aggrandizement.
Instead, proportionality in just war theory implies that only war can correct the wrong suffered. The wrong to be corrected must be grave. Insults to national pride or need to maintain reputation are insufficient reasons to use war. So, too, for example would be economic harm that does not materially destroy a national economy.
War, even a just war, always involves the loss of innocent life and destruction of things that are simply too near the battle area. The inevitability of this so-called “collateral damage” means that war is necessarily a blunt instrument. This reality undergirds the just war notion of proportionality.
Consider the current conflict in Libya. In your opinion, would war be justified according to the just war principle of proportionality?
Michael T. Corgan, Associate Chair and Associate Professor of International Relations, Boston University