must be treated as prisoners of war. Suspected terrorists who are captured during an armed conflict, without having participated in the hostilities, may be detained only in accordance with the GC IV, and are entitled to a regular trial. Countries that have signed the UN Convention Against Torture have committed themselves not to use torture on anyone for any reason. After a conflict has ended, persons who have committed any breach of the laws of war, and especially atrocities, may be held individually accountable for war crimes through process of law. Key provisions and principles applicable to civilians The Fourth Geneva Convention focuses on the civilian population. The two additional protocols adopted in 1977 extend and strengthen civilian protection in international (AP I) and non-international (AP II) armed conflict: for example, by introducing the prohibition of direct attacks against civilians. A "civilian" is defined as "any person not belonging to the armed forces", including non-nationals and refugees. However, it is accepted that operations may cause civilian casualties. Luis Moreno Ocampo, chief prosecutor of the international criminal court, wrote in 2006: "International humanitarian law and the Rome statute permit belligerents to carry out proportionate attacks against military objectives, even when it is known that some civilian deaths or injuries will occur. A crime occurs if there is an intentional attack directed against civilians (principle of distinction) ... or an attack is launched on a military objective in the knowledge that the incidental civilian injuries would be clearly excessive in relation to the anticipated military advantage (principle of proportionality)." The provisions and principles of IHL which seek to protect civilians are: IHL provisions and principles protecting civilians Principle of distinction The principle of distinction protects civilian population and civilian objects from the effects of military operations. It requires parties to an armed conflict to distinguish at all times, and under all circumstances, between combatants and military objectives on the one hand, and civilians and civilian objects on the other; and only to target the former. It also provides that civilians lose such protection should they take a direct part in hostilities. The principle of distinction has also been found by the ICRC to be reflected in state practice; it is therefore an established norm of customary international law in both international and non-international armed conflicts. Necessity and proportionality Necessity and proportionality are established principles in humanitarian law. Under IHL, a belligerent may