If there’s a single thing that separates legitimate warfare from simple terrorism, it’s the effort to distinguish civilians from soldiers, and combatants from noncombatants. That’s not to say that noncombatants don’t die in “legitimate” wars, or that states don’t accept civilian deaths as a matter of course. At the same time, it matters that those actions aren’t war aims—that states are trying to distinguish between combatants and noncombatants.