To Do, To Die, To Reason Why offers a new account of the ethics of war and the legal regulation of war. It is especially concerned with the conduct of individuals, including whether they are required to follow orders to go to war, what moral constraints there are on killing in war, what makes people liable to be killed in war, and the extent to which the laws of war ought to reflect the morality of war. Victor Tadros defends a largely anti-authority view about the morality of war, and notable moral constraints on killing in war, such as the Doctrine of Doing and Allowing and a version of the Doctrine of Double Effect. However, he argues that a much wider range of people are liable to be harmed or killed in war than is normally thought to be the case, on grounds of both causal involvement and fairness. And it argues that the laws of war should converge much more closely with the morality of war than is currently the case.