‘There is no moral justification, and no truly persuasive legal reason for treating perpetrators of atrocities in internal conflicts more leniently than those engaged in international wars.’ If moral principles have always called for atrocities committed in internal armed conflicts to be criminalised, state sovereignty has resisted the application of the concept of war crimes to internal armed conflicts for a very long time. The view expressed by the International Committee of the Red Cross (ICRC) in 1993, reflected very well a widely held view when it commented on the establishment of the International Criminal Tribunal for the former Yugoslavia (ICTY): ‘according to international humanitarian law as it stands today, the notion of war crimes is limited to situations of international armed conflict’. In 1993, the Commission of Experts on Yugoslavia adopted a similar conservative approach by concluding that the scope and the content of customary international law applicable to internal armed conflict was ‘debatable’ and did not incorporate individual criminality. Common Article 3, for example, was found to be part of customary law but according to this commission, violations of common Article 3 do not amount to war crimes. The Secretary-General followed some of these conclusions, stressing that the ICTY shall apply ‘rules of international humanitarian law which are beyond any doubt part of customary law’ but failed to include Article 3 or Protocol II within the lists of instruments which have beyond doubt become part of international customary law.