Combatants in war inflict untold devastation. They lay waste to the environment, destroy cultural heritage, wound, maim, and kill. Most importantly, they kill. These are deeds that would normally be morally abhorrent. People have, as a matter of justice, a duty to respect others’ rights to life. To kill, in almost any other context besides war, is to breach that duty. If a country is at war, and a concerned citizen is deciding whether or not to fight, it is killing that must first be justified. 1 There are two ways to justify acts that would, ordinarily, breach our duties of justice. The first is to maintain that in the relevant situation the duty does not in fact obtain, so there is no corresponding breach. The second is to argue that, while these acts are indeed unjust, there is some other, more compelling moral consideration, which justifies these breaches of duty. For example, it may be impossible to avoid