International Humanitarian Law
Sometimes called the law of war, international humanitarian law limits the ways in which wars can be conducted. It differs from rules regarding the use of force because it applies to ongoing wars rather than circumstances that could lead to wars. International humanitarian law serves two main goals: protecting the safety of non-combatants and restricting the weapons and tactics that may be used during wars. These rules apply to both international armed conflicts involving multiple sovereign states and non-international armed conflicts within a single state, although non-international armed conflicts are subject to fewer restrictions. Any state or other entity involved in a conflict is equally subject to international humanitarian law, regardless of whether it started the conflict.
The four Geneva Conventions of 1949 comprise the main sources of international humanitarian law. Two agreements known as the Additional Protocols of 1977 have supplemented the protections provided by the Geneva Conventions regarding victims of armed conflicts. (Additional Protocol I applies to international armed conflicts, while Additional Protocol II applies to non-international armed conflicts.) Other agreements cover certain categories of weapons, tactics, people, or property more specifically. These include conventions addressing biological weapons, chemical weapons, and anti-personnel mines, as well as conventions addressing children involved in wars and cultural property during wars.
Protections for Non-Combatants and Former Combatants
International humanitarian law requires respect for the safety of civilians, military doctors and clergy, and other people who are not directly involved in armed conflicts. People classified as former combatants, such as prisoners of war and wounded or ill soldiers, also receive guarantees of humane treatment. For example, the armed forces of a state must not kill an enemy soldier once they have surrendered or once it becomes clear that they cannot continue fighting. A party that captures or otherwise gains control over an injured former combatant must provide them with proper medical treatment.
Former combatants who are prisoners of war are entitled to certain conditions during detention. Meanwhile, non-combatants in areas controlled by enemy armed forces have certain basic rights. Among other things, they must be granted access to food, shelter, and medical care.
Restrictions on Weapons and Tactics
The other central pillar of international humanitarian law involves prohibitions against unnecessarily harmful or cruel forms of warfare. It also bans any methods of war that do not allow those using them to distinguish between combatant and non-combatant targets. In addition, international humanitarian law forbids the use of weapons or tactics that cause severe or lasting harm to the environment. Prohibited weapons thus include chemical and biological weapons, exploding bullets, and blinding lasers.