Non-lethal weapons and international humanitarian law

This report evaluates the possible use of non-lethal weapons in the light of international treaty law and customary law pertaining to the legality of various kinds of weapons. The purpose is to determine to which extent non-lethal weapons may be used by Norwegian forces, both in armed conflict as well as in peacekeeping operations. Possible limitations or prohibitions on non-lethal weapons are discussed with regard to the general rules in international humanitarian law on proportionality, as well as the more specific legal regimes pertaining to chemical and biological weapons, anti-personnel landmines, etc. Being particularly relevant to non-lethal weapons, the Chemical Weapons Convention is subject to a thorough discussion on its general scope of application regarding non-lethal chemicals. The report concludes that if a type of weapon or ammunition is prohibited by general or specific rules, the possible classification as ”non-lethal” does not eliminate the prohibition. However, certain weapons are only prohibited in armed conflict, and thus may be used in law enforcement assignments, for example in peacekeeping operations. This would for instance apply to non-lethal chemical weapons.