As stated in Article 93 of the UN Charter, all 193 UN members are automatically parties to the Court’s statute. Non-UN members may also become parties to the Court’s statute under the Article 93(2) procedure. For example, before becoming a UN member state, Switzerland used this procedure in 1948 to become a party. And Nauru became a party in 1988. Once a state is a party to the Court’s statute, it is entitled to participate in cases before the Court. However, being a party to the statute does not automatically give the Court jurisdiction over disputes involving those parties. The issue of jurisdiction is considered in the two types of ICJ cases: contentious issues and advisory opinions.
In contentious cases (adversarial proceedings seeking to settle a dispute), the ICJ produces a binding ruling between states that agree to submit to the ruling of the court. Only states may be parties in contentious cases. Individuals, corporations, parts of a federal state, NGOs, UN organs and self-determination groups are excluded from direct participation in cases, although the Court may receive information from public international organizations. This does not preclude non-state interests from being the subject of proceedings if one state brings the case against another. For example, a state may, in case of “diplomatic protection”, bring a case on behalf of one of its nationals or corporations.
Jurisdiction is often a crucial question for the Court in contentious cases. (See Procedure below.) The key principle is that the ICJ has jurisdiction only on the basis of consent. Article 36 outlines four bases on which the Court’s jurisdiction may be founded.
- First, 36(1) provides that parties may refer cases to the Court (jurisdiction founded on “special agreement” or “compromis”). This method is based on explicit consent rather than true compulsory jurisdiction. It is, perhaps, the most effective basis for the Court’s jurisdiction because the parties concerned have a desire for the dispute to be resolved by the Court and are thus more likely to comply with the Court’s judgment.
- Second, 36(1) also gives the Court jurisdiction over “matters specifically provided for … in treaties and conventions in force”. Most modern treatieswill contain a compromissory clause, providing for dispute resolution by the ICJ. Cases founded on compromissory clauses have not been as effective as cases founded on special agreement, since a state may have no interest in having the matter examined by the Court and may refuse to comply with a judgment. For example, during the Iran hostage crisis, Iran refused to participate in a case brought by the US based on a compromissory clause contained in the Vienna Convention on Diplomatic Relations, nor did it comply with the judgment. Since the 1970s, the use of such clauses has declined. Many modern treaties set out their own dispute resolution regime, often based on forms of arbitration.
- Third, Article 36(2) allows states to make optional clause declarations accepting the Court’s jurisdiction. The label “compulsory” which is sometimes placed on Article 36(2) jurisdiction is misleading since declarations by states are voluntary. Furthermore, many declarations contain reservations, such as exclusion from jurisdiction certain types of disputes (“ratione materia”).The principle of reciprocity may further limit jurisdiction. As of February 2011, sixty-six states had a declaration in force. Of the permanent Security Council members, only the United Kingdom has a declaration. In the Court’s early years, most declarations were made by industrialized countries. Since the Nicaragua Case, declarations made by developing countries have increased, reflecting a growing confidence in the Court since the 1980s. Industrialized countries however have sometimes increased exclusions or removed their declarations in recent years. Examples include the USA, as mentioned previously and Australia who modified their declaration in 2002 to exclude disputes on maritime boundaries (most likely to prevent an impending challenge from East Timor who gained their independence two months later).
- Finally, 36(5) provides for jurisdiction on the basis of declarations made under the Permanent Court of International Justice’s statute. Article 37 of the Statute similarly transfers jurisdiction under any compromissory clause in a treaty that gave jurisdiction to the PCIJ.
- In addition, the Court may have jurisdiction on the basis of tacit consent (forum prorogatum). In the absence of clear jurisdiction under Article 36, jurisdiction will be established if the respondent accepts ICJ jurisdiction explicitly or simply pleads on the merits. The notion arose in the Corfu Channel Case (UK v Albania) (1949) in which the Court held that a letter from Albania stating that it submitted to the jurisdiction of the ICJ was sufficient to grant the court jurisdiction.
An advisory opinion is a function of the Court open only to specified United Nations bodies and agencies. On receiving a request, the Court decides which States and organizations might provide useful information and gives them an opportunity to present written or oral statements. Advisory Opinions were intended as a means by which UN agencies could seek the Court’s help in deciding complex legal issues that might fall under their respective mandates.
In principle, the Court’s advisory opinions are only consultative in character, but they are influential and widely respected. Whilst certain instruments or regulations can provide in advance that the advisory opinion shall be specifically binding on particular agencies or states, they are inherently non-binding under the Statute of the Court. This non-binding character does not mean that advisory opinions are without legal effect, because the legal reasoning embodied in them reflects the Court’s authoritative views on important issues of international law and, in arriving at them, the Court follows essentially the same rules and procedures that govern its binding judgments delivered in contentious cases submitted to it by sovereign states.
An advisory opinion derives its status and authority from the fact that it is the official pronouncement of the principal judicial organ of the United Nations.
Advisory Opinions have often been controversial because the questions asked are controversial or the case was pursued as an indirect way of bringing what is really a contentious case before the Court. Examples of advisory opinions can be found in the section advisory opinions in the List of International Court of Justice cases article. One such well-known advisory opinion is the Nuclear Weapons Case.