The least discussed, and yet arguably the most important, principle of international humanitarian law and the corresponding war crimes law is humane treatment. The other main principles – discrimination, necessity, and proportionality – have been extensively written about, although not, as we will see in subsequent chapters, always clearly explained and justified. But the idea of humane treatment, which is mentioned many times in The Hague and Geneva Conventions, the main sources of war crimes law, has not been subject to the same scrutiny and defense. At least one reason for this apparent lacuna is that humane treatment may simply be thought of as shorthand for that treatment which satisfies the other principles of jus in bello regulations. I will dispute this simple explanation in this chapter and then set out a clear account of the principle of humane treatment. I will also connect the Grotian principle of humanity to the contemporary idea of humane treatment.

The principle of humane treatment is a principle that calls both for the minimizing of suffering and for merciful treatment, as a way of displaying honor. At its core, humane treatment is related to the principle of humanity that involves treating another person as a fellow human, as a member of the same group, the human race, rather than in any number of other ways that take account of his or her otherness.