 This has deep moral foundations: combatants in war are morally required to reduce the risk to innocents until doing so further would involve an unreasonably high cost to them, which they cannot be required to bear. Working out when that point is reached involves thinking through: soldiers’ role-obligations to assume risks; the difference between doing harm to civilians and allowing it to happen to oneself or one’s comrades-in-arms; the importance of associative duties to protect one’s comrades; and all the considerations already adduced in favour of Moral Distinction. This calculus is very hard to perform. My own view is that combatants ought to give significant priority to the lives of civilians (Walzer and Margalit 2009; McMahan 2010b). This is in stark contrast to existing practice (Luban 2014).