Restricting weapons in international humanitarian law

Conflict kills and injures thousands of people every year, but those numbers would be much higher if there were no banned weapons. Principles of international humanitarian law prohibit and regulate the use of certain weapons, and international agreements ban some types completely, while limiting others. Weapons are banned based on three principles.

Weapons must not be indiscriminate

Attacks can only be directed at combatants and military objectives. Weapons must be able to be used in such a way that they discriminate between combatants and civilians. If a weapon cannot be directed at a specific military target, or if its effects cannot be controlled, it is indiscriminate. Anti-personnel landmines and booby traps are illegal indiscriminate weapons, because once they are set up, they can’t distinguish between a legitimate military target and a civilian one.

Weapons must not cause unnecessary suffering or superfluous injury

Weapons that cause more harm than is necessary to achieve a military aim are illegal. For example, a combatant who has been shot is unlikely to take further part in hostilities; exploding bullets cause extra and unnecessary harm to combatants without furthering military objectives. Weapons that injure by fragments that cannot be detected by X-ray are specifically banned. They have no legitimate military purpose, and only exist to prolong suffering and prevent treatment.