Compulsory jurisdiction is the jurisdiction of the International Court of Justice (ICJ).

Membership in the United Nations does not automatically subject a country to the jurisdiction of the ICJ. The ICJ will hear a case only if all the countries involved in the case consent to its jurisdiction. Some countries automatically accept the jurisdiction of the court. Other countries automatically accept the court's compulsory jurisdiction but reserve the right to opt out of ICJ proceedings on matters that are of vital national interest. (Although the word compulsory is used, a country may choose not to recognize the ICJ's jurisdiction. Participation is voluntary.)

United States and compulsory jurisdiction

On April 6, 1984, the United States informed the United Nations that it would not accept the compulsory jurisdiction of the ICJ in disputes involving Central America. On April 9, 1984, Nicaragua asked the ICJ to hear a case against the United States.[1940] Nicaragua asserted that the United States had violated customary and conventional international law by engaging in and supporting insurgent military and paramilitary activities against the Nicaraguan government. (See Nicaragua vs. United States)

The United States argued that its notification of April 6, 1984, deprived the ICJ of jurisdiction over the case. The ICJ disagreed and accepted the case. Though the United States had withdrawn from the case, the ICJ heard Nicaragua's arguments. On June 27, 1986, In a 12-3 decision, the majority of the Court ruled the United States was "in breach of its obligation under customary international law not to use force against another state" and ordered the US pay reparations...although it never did.