Law of international armed conflict
(1) (s) “Law of international armed conflict” means all the principles and rules of treaty and customary international law binding on a State and governing armed conflict between States; the term “law of international armed conflict” is synonymous with “international humanitarian law relating to international armed conflict”.
- The law of international armed conflict applies to all situations of international armed conflict as de-fined in Rule 1 (r). The law of international armed conflict must be clearly distinguished from the law regulating the legality of the resort to armed force by States (“jus ad bellum”).
- As far as the law of international armed conflict is concerned, it was common in the past to distinguish between “Hague law” (the law governing the conduct of hostilities) and “Geneva law” (the law aimed at the protection of victims of armed conflict). Today, there is general agreement that “these two branches of the law applicable in armed conflict have become so closely interrelated that they are considered to have gradually formed one single complex system, known today as international humanitarian law”.
- Different terms are used to describe the law of international armed conflict, such as “international humanitarian law”, “jus in bello”, “law of war”, “law of armed conflict”. The Group of Experts was, however, in agreement that this is a semantic rather than a substantive issue. Therefore, they agreed to use both terms synonymously. However, in order to clearly distinguish between international and non-international armed conflicts it was decided to use the terms “law of international armed conflict’ and “international humanitarian law relating to international armed conflict”.
- While treaties are binding only upon Contracting Parties, customary international law is binding on all States, except for those States that — from the very outset of the evolution of a specific customary rule — qualify as persistent objectors.
- ICJ, Nuclear Weapons Advisory Opinion, at page 256.