International humanitarian law

• Civilians and civilian objects may not be attacked in any circumstances. Parties to a conflict must at all times distinguish between 'military objectives' and civilians and civilian objects.
• Attacks on military objectives are prohibited if they are likely to involve excessive casualties among the civilian population or disproportionate damage to civilian objects or the environment. When attacking, the parties to a conflict must take all possible precautions to protect the civilian population and civilian objects.
• It is prohibited to use civilians as human shields.
• It is prohibited to misuse the emblems of the Geneva Convention.
• Weapons that are indiscriminate or cause unnecessary suffering or severe damage to the environment are prohibited. This includes biological and chemical weapons, blinding laser weapons or expanding bullets.

• The four Geneva Conventions and their Additional Protocols protect persons who are not participating, or who are no longer participating, in hostilities. Civilian internees, prisoners of war and other vulnerable persons must not be mistreated and the wounded must be taken in and cared for.
• Additional Protocol I of 1977, the Hague Convention of 1907 and the Convention on Certain Conventional Weapons of 1980 and its Protocols restrict the means and methods of warfare.
• Most of the obligations regarding the conduct of hostilities are of a customary nature. 

In a situation of armed conflict, including occupation, all parties, whether state forces or non-state armed groups, must respect international humanitarian law:

• Armed conflicts between states (international armed conflicts) are subject to the rules set out in the four Geneva Conventions, Additional Protocol I of 1977, the Hague Convention of 1907 and the relevant customary law.
• A more limited range of treaty-based norms applies to non-international armed conflicts. Article 3 common to the Geneva Conventions and Additional Protocol II of 1977 are applied, as well as the relevant customary law.

Not only the parties to a conflict, but also all individuals participating in an armed conflict, must comply with international humanitarian law. As a rule, grave breaches of international humanitarian law are war crimes. Examples of war crimes include:

• torture and inhuman treatment of captives
• rape
• attacks on the civilian population
• unlawful displacement of the civilian population
• taking hostages
• recruiting child soldiers  

In the event of grave breaches of the Geneva Conventions, every state has a duty to either prosecute the suspected perpetrators in a criminal court or to hand them over to another state or an international criminal tribunal for prosecution (principle of aut dedere aut judicare).