2 minute read

International Law

Sources Of International Law



The INTERNATIONAL COURT OF JUSTICE (ICJ) was established in 1945 as the successor to the Permanent International Court of Justice (PICJ), which was created in 1920 under the supervision of the LEAGUE OF NATIONS (the precursor to the United Nations). The PICJ ceased to function during WORLD WAR II and was officially dissolved in 1946. The ICJ is a permanent international court located in the Hague, Netherlands, and it is the principal judicial organ of the United Nations (UN). It consists of 15 judges, each from a different state. The judges are elected by the UN General Assembly and the UN Security Council and must receive an absolute majority from both in order to take office.



The ICJ has jurisdiction only over states that have consented to it. It follows that the court cannot hear a dispute between two or more state parties when one of the parties has not accepted its jurisdiction. This can happen even where the non-consenting party adheres to the court's statute, for mere adherence to the statute does not imply consent to its tribunals. In addition, the court does not have jurisdiction over disputes between individuals or entities that are not states (I.C.J. Stat. art. 34(1)). It also lacks jurisdiction over matters that are governed by domestic law instead of international law (art. 38(1)).

Article 38(1) of the ICJ Statute enumerates the sources of international law and provides that international law has its basis in international custom, international conventions or treaties, and general principles of law. A rule must derive from one of these three sources in order to be considered international law.

Custom Customary international law is defined as a general PRACTICE OF LAW under article 38(1)(b). States follow such a practice out of a sense of legal obligation. Rules or principles must be accepted by the states as legally binding in order to be considered rules of international law. Thus, the mere fact that a custom is widely followed does not make it a rule of international law. States also must view it as obligatory to follow the custom, and they must not believe that they are free to depart from it whenever they choose, or to observe it only as a matter of courtesy or moral obligation. This requirement is referred to as opinio juris.

Some criticism against customary international law is directed at its subjective character and its inconsistency. States vary greatly in their opinions and interpretations of issues regarding international law. Thus, it is almost impossible to find enough consistency among states to draw a customary international rule from general practice. In addition, even if one state or judge finds that a practice is a rule of customary international law, another decision maker might reach a different conclusion. Altogether, the process of establishing rules of customary international law is lengthy and impeded by today's fast-changing world.

Conventions and Treaties Conventional international law includes international agreements and legislative treaties that establish rules expressly recognized by consenting states. Only states that are parties to a treaty are bound by it. However, a very large number of states voluntarily adhere to treaties and accept their provisions as law, even without becoming parties to them. The most important treaties in this regard are the Genocide Convention, the Vienna conventions, and the provisions of the UN Charter.

Additional topics

Law Library - American Law and Legal InformationFree Legal Encyclopedia: Internal Revenue Service - Duties And Powers to Joint willInternational Law - Sources Of International Law, Un Charter And United Nations, Further Readings, Cross-references