Full Idea
There is simply no satisfactory understanding of proportionality in war that can be applied independently of whether the acts that are evaluated support a just or an unjust cause.
Gist of Idea
Proportionality in fighting can't be judged independently of the justice of each side
Source
Jeff McMahan (Killing in War [2009], 1.3)
Book Reference
McMahan,Jeff: 'Killing in War' [OUP 2009], p.32
A Reaction
He rejects traditional just war theory, which sees both sides as morally equal in combat, and hence equally subject to the principles of proportional response. But the just can then be harsher, when their just principles should make them milder.