The body of law that governs the legal relations between or among states or nations.
To qualify as a subject under the traditional definition of international law, a state had to be sovereign: It needed a territory, a population, a government, and the ability to engage in diplomatic or foreign relations. States within the United States, provinces, and cantons were not considered subjects of international law, because they lacked the legal authority to engage in foreign relations. In addition, individuals did not fall within the definition of subjects that enjoyed rights and obligations under international law.
A more contemporary definition expands the traditional notions of international law to confer rights and obligations on intergovernmental international organizations and even on individuals. The UNITED NATIONS, for example, is an international organization that has the capacity to engage in treaty relations governed by and binding under international law with states and other international organizations. Individual responsibility under international law is particularly significant in the context of prosecuting war criminals and the development of international HUMAN RIGHTS.
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...