“War is murder!”
Wrong! Well… sometimes it is, but other times it isn’t.
Hear me out.
This statement can’t be universalized without coming into conflict with property norms (or itself, for that matter).
Here’s why: the word “murder” as defined in the context of property disputes over the use of scarce resources — in this case human bodies — implies physical trespass. Killing someone who has the means, motive, and opportunity to murder you while they are in the act of attempting said murder is legally and morally justifiable by the principle of estoppel. By rejecting property norms, one proportionally excludes oneself from appealing to property norms in one’s own defense.
This is the principle underlying the “Castle Doctrine”.
The same theoretically applies to war. One can not simultaneously provoke a physical conflict over the use of a resource and assert property rights over said resource absent evidence of a superior link. We all understand this to be true in our day to day lives. One can not be the trespass victim and the trespasser simultaneously. One can not be the rape victim and the rapist simultaneously. One can not be the murder victim and the murderer simultaneously. When a physical conflict occurs over the use of some resource, the current users are assumed prima facie to have the most superior link to said resource, and those who are initiating the physical conflict (war, in this case) are assumed to be the aggressors, or murderers.
The current users are therefore assumed to be acting in self-defense.
Of course, this assumes that non-combatants would be among the casualties, or that they could be if those acting in their defense were to fail. If for some reason they weren’t and the conflict only affected professional soldiers who agreed to the terms of the physical conflict ahead of time, this would all go out the window as it would be like trying to apply property norms and ethics to a football game or an MMA fight.