IHL Treaties and the Regulation of Weapons

Types of weapons banned under international law

Specific types of weapons are banned entirely, such as anti-personnel landmines, and biological and chemical weapons. Other weapons are subject to limits – such as the restrictions on the use of booby-traps. Weapons are constantly being developed and the law evolves accordingly.

The way weapons are used can be as important as what they do. For example, incendiary weapons, designed to spread fire or to burn, are prohibited in all circumstances against civilians. But lawful use against soldiers is possible. Some weapons may be lawful for use against buildings or enemy tanks but not if directed at combatants.

Where is the law about weapons written and how is it enforced?

International humanitarian law is based on the Geneva Conventions and its two Additional Protocols. However, the main laws about weapons are contained in separate conventions addressing specific types of weapons. These are just as legally binding, and include the 1972 Biological Weapons Convention, the 1980 Conventional Weapons Convention and the 1997 Ottawa Convention on anti-personnel landmines.

Alleged breaches of the law can be tried in national courts, or by the International Criminal Court at the Hague. There are many breaches of the law. Many appalling and desperate things happen during war, and these only serve to reinforce the need for international humanitarian law and mechanisms to enforce the rules of war.

Weapons specifically banned in treaties

Weapon	Treaty
Explosive projectiles weighing less than 400 grams	Declaration of Saint Petersburg (1868)
Bullets that expand or flatten in the human body	Hague Declaration (1899)
Poison and poisoned weapons	Hague Regulations (1907)
Chemical weapons	Geneva Protocol (1925) Convention on the Prohibition of Chemical Weapons (1993)
Biological weapons	Geneva Protocol (1925) Convention on the Prohibition of Biological Weapons (1972)
Weapons that injure by fragments which, in the human body, escape detection by X-rays	Protocol I (1980) to the Convention on Certain Conventional Weapons
Incendiary weapons	Protocol III (1980) to the Convention on Certain Conventional Weapons
Blinding laser weapons	Protocol IV (1995) to the Convention on Certain Conventional Weapons
Mines, booby traps and "other devices"	Protocol II, as amended (1996), to the Convention on Certain Conventional Weapons
Anti-personnel mines	Convention on the Prohibition of Anti-Personnel Mines (Ottawa Treaty) (1997)
Explosive remnants of war	Protocol V (2003) to the Convention on Certain Conventional Weapons
Cluster munitions	Convention on Cluster Munitions (2008)