International humanitarian law
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)."