Decisions of international courts and arbitrators, as well as judgments of national courts, are fundamental elements of modern public international law. The International Law Reports is the only publication in the world wholly devoted to the regular and systematic reporting in English of such decisions. It is therefore an absolutely essential work of reference. Volume 166 reports on, amongst others, the judgment of the International Court of Justice on Ahmadou Sadio Diallo (Republic of Guinea v. Democratic Republic of the Congo) and the judgment of the European Court of Human Rights on Öcalan v. Turkey (No. 2).