ICJ - Jurisdiction & Sources of Law

The scope of the ICJ's jurisdiction and the legal sources it applies.

• Contentious jurisdiction: May be invoked regarding legal disputes concerning any question of international law, interpretation of a treaty, or any fact constituting a breach of an international obligation — all of these.
• Optional Clause (Article 36): A declaration made under Article 36 (originally under the PCIJ Statute) is deemed to establish compulsory jurisdiction between states that have made such declarations.
• Non-universal bindingness: ICJ jurisdiction is not binding on all members of the UNO — only on states that have consented (via special agreement, treaty clause, or Article 36 declaration).
• Applicable law (Article 38): In deciding disputes, the ICJ applies international conventions/treaties, international custom, and the general principles of law recognized by civilized nations — all of these, along with judicial decisions and teachings as subsidiary means.
• Article 38(1)(b): Specifically recognizes customary law (international custom), General Principle recognized by civilized nations and Conventions or Treaties as a source of international law.