Evidence Before the International Court of Justice : Issues of Fact and Questions of Law In the Determination of International Custom

Evidence directly serves the purposes of international adjudication, which is the settlement of a dispute. The rules on evidence play before an international court however a more fundamental role, since an international court, by way of its activity, might be seen to be contributing actively to the elaboration process of the applicable rules having customary nature. In that respect, the examination of the rules applicable before the ICJ shows that the Court has large power to direct the parties’ activities in the presentation of evidence and is allowed an active role in the taking of evidence. This power can be used, according to the iura novit curia principle, chiefly when the determination of the factual element comprised in a customary rule is at issue. This line is to be followed especially with respect to peremptory norms of international law.