The United Nations Charter is the foundational treaty and constituent instrument of the United Nations, serving as the core of public international law. It was signed on June 26, 1945, in San Francisco, and came into force on October 24, 1945, after ratification by the five permanent members of the Security Council and a majority of other signatories. The Charter was drafted in the aftermath of World War II to replace the League of Nations Covenant and solve the problem of recurring global conflict, with the primary purpose being to "save succeeding generations from the scourge of war".
The Charter consists of a Preamble and 111 Articles divided into 19 Chapters. Its mechanism is built on the purposes outlined in Article 1, which include maintaining international peace and security, and promoting human rights and international cooperation. A key provision is Article 2(4), which mandates that all member states "shall refrain in their international relations from the threat or use of force". The Charter establishes the principal organs of the UN, such as the General Assembly and the Security Council, and the Statute of the International Court of Justice is an integral part of the Charter (Article 92).
The Charter has not changed recently, but it has been amended a few times, notably in 1963, 1965, and 1973. These amendments primarily expanded the membership of the Security Council (in Article 23) and the Economic and Social Council (in Article 61). The core amendment process, detailed in Article 108, remains unchanged, requiring a two-thirds vote in the General Assembly and ratification by two-thirds of the members, including all five permanent members of the Security Council.