this is michael walzer. he is a professor emeritus at princeton university and author of any number of books. but there's one that i would recommend to you. it's called just and unjust wars, a moral argument with historical illustrations published in 1977. i read it as a college freshman. it has been through five editions since then, and it is the single most lucid and intelligent sudden dis of the ethical aspects of war that i can commend to you. michael walzer talks about the principle of double effect. this is a concept that really goes back before michael walzer. but he offers a good modern formulation that is relevant to what it is that i'm talking about today. double effect, walzer writes is a way of exercising the absolute prohibition against attacking noncombatants with a legitimate conduct of military activity, which may unavoidably expose noncombatants to harm. its key condition is that the intention of the actor is good. that is to say, the actor, or the person who is responsible for making this p