The Contemporary Legal Basis of International Humanitarian Law and Its Fundamental Principles

1. Introduction As noted in Chapter 1, international humanitarian law (IHL) or the jus in bello (law in war) is one of the oldest bodies of international law and aims to regulate the conduct of States and individual participants in an armed conflict, and to protect people and property. The law seeks to balance twin objectives: the needs of the armed forces of a State (or non-State group) to prosecute the armed conflict, and the humanitarian need to protect those who do not, or no longer, take direct part in the hostilities (known as hors de combat or “out of combat”). Initially, the law only regulated the conduct of States in international armed conflicts; now, the law governs the conduct of States and non-State actors, in international and non-international armed conflicts, and contains a plethora of rules, drawn from treaties, customary international law and other sources, covering weapons, methods of warfare, targeting and the treatment of persons hors de combat . All of these rules find their origins in more general overarching principles of IHL; it is these general principles and specific sources that are explored in this chapter. 2. The law of armed conflict: purpose, concepts, scope, application As stated above, IHL seeks to regulate conduct in armed conflicts. At first glance, such an aim would seem nonsensical – how can one regulate warfare? How can you prohibit certain kinds of killing, wounding and property destruction, while permitting other kinds of violence? Indeed, this very sentiment was expressed by Admiral Lord Fisher, First Sea Lord of the Royal Navy: “the humanizing of War! You might as well talk of the humanizing of Hell … As if war could be civilized! If I'm in command when war breaks out I shall issue my order – ‘The essence of war is violence. Moderation in war is imbecility. Hit first, hit hard, and hit everywhere.’” However, contrary to Fisher's bleak outlook, history has shown that over the centuries many societies, from many different parts of the globe, have attempted to place limitations on conduct in armed conflict.