Civil war is still the prevalent form of armed conflict today. Nevertheless, its regulation in treaty law remains rudimentary compared to the regulation of international armed conflict. However, under the influence of practice, a number of customary rules regulating this type of conflict have evolved. Antonio Cassese played a prominent role in the identification of these customary rules, first as a scholar and then as a judge at the International Criminal Tribunal for the former Yugoslavia and President of the Independent Commission of Inquiry on Darfur. A study published by the International Committee of the Red Cross in 2005 took this identification process further and provides a comprehensive assessment of these rules. It indicates that the divide between the regulation of internal and international armed conflicts has been narrowed down considerably.