United Nations


  • Established: 1945
  • Membership: 193 States
  • Non-member States: Holy See, State of Palestine
  • Secretary-General: Antonio Guterres (2017-2021)
  • Deputy Secretary-General: Amina J. Mohammed (2017-    )



In 1945, representatives of 50 countries met in San Francisco at the United Nations Conference on International Organization to draw up the United Nations Charter. Those delegates deliberated on the basis of proposals worked out by the representatives of China, the Soviet Union, the United Kingdom, and the United States at Dumbarton Oaks, United States, in August-October 1944. The Charter was signed on 26 June 1945 by the representatives of the 50 countries. Poland, which was not represented at the Conference, signed it later and became one of the original 51 member states.

As mandated by its Charter, maintaining international peace and security is the central purpose of the United Nations. Although the Charter does not directly reference nuclear weapons, some of the UN's major goals include halting the spread of arms and reducing and eventually eliminating all weapons of mass destruction. Since its establishment, the UN has been an ongoing forum for nonproliferation and disarmament treaties, negotiations, deliberations, and expert studies. The principal UN organs that deal with international peace and security, arms control, disarmament, and nonproliferation are the UN Security Council (UNSC), the First Committee of the General Assembly (UNGA), and the UN Office for Disarmament Affairs (UNODA).

Under Article 26 of the UN Charter, the UN Security Council (UNSC) is tasked with the "establishment and maintenance of international peace and security... and the establishment of a system for the regulation of armaments." The UNSC is composed of 15 member states: five permanent members with veto powers (China, France, the Russian Federation, the United Kingdom and the United States) and ten additional members, each elected by the General Assembly for a term of two years. After determining "the existence of any threat to the peace, breach of the peace, or an act of aggression," the UNSC may recommend or take preventative or enforcement measures including economic or political measures or the use of force. As such, the Security Council is the only international body that can authorize punitive measures such as sanctions or military action against a state. In the area of nonproliferation, the UNSC has authorized mandatory sanctions against Iraq, the DPRK, and Iran; created the Monitoring, Verification and Inspection Commission (UNMOVIC); and established other important subsidiary organs such as the Counter-Terrorism Committee and the 1540 Committee. For more detail on the Security Council and recent developments in the nonproliferation field, see the Security Council section.

The UN General Assembly (UNGA) is a representative international body tasked to consider, among other things, disarmament and international security issues. On 24 January 1946, the first General Assembly session passed Resolution 1(I) on the "Establishment of a Commission to Deal with the Problems Raised by the Discovery of Atomic Energy," which addressed concerns about the dangers of nuclear proliferation. Since then, the body annually adopts resolutions and decisions on nonproliferation, disarmament, and arms control on the recommendation of its First Committee, which considers issues relating to international peace and security. Some of the most notable decisions related to disarmament, nonproliferation, and arms control include the endorsement of the Treaty on the Nonproliferation of Nuclear Weapons (NPT) in 1968; the Biological and Toxin Weapons Convention (BTWC) in 1972; the Chemical Weapons Convention (CWC) in 1992; the Comprehensive Test Ban Treaty (CTBT) in 1996; and the Arms Trade Treaty (ATT) in 2013. The General Assembly has also held three special sessions on disarmament (SSOD) in 1978, 1982, and 1988. The UN Disarmament Commission (UNDC) is a deliberative body and a subsidiary organ of the UNGA. Reestablished in 1978, it is tasked to formulate guidelines, principles, and recommendations for disarmament-related issues. For more detail on the General Assembly and recent developments in the nonproliferation field, see the pages for the General Assembly and the First Committee.

The UN Office for Disarmament Affairs (UNODA) was originally established as the Department of Disarmament Affairs (DDA) in 1982 upon the recommendation of the General Assembly's second special session on disarmament (SSOD II) and functioned as a department until 1992. From 1992-1997 it functioned as a Center under the Department of Political Affairs. The DDA was re-established in 1998 as part of the Secretary-General's program for reform in accordance with his report A/51/950 to the General Assembly. In 2007, the name was changed to the United Nations Office for Disarmament Affairs (UNODA).

UNODA promotes the goals of disarmament and nonproliferation as well as strengthening the international regimes dealing with weapons of mass destruction. It also promotes disarmament efforts in the area of conventional weapons, especially land mines and small arms, which are the weapons of choice in contemporary conflicts. UNODA is composed of five branches: Conference on Disarmament Secretariat & Conference Support Branch, the Weapons of Mass Destruction Branch, the Conventional Arms Branch, the Regional Disarmament Branch, and the Monitoring, Database and Information Branch. For more detail on the department's role in nonproliferation and disarmament, see the page for the UN Office for Disarmament Affairs.


The central mission of the UN is to maintain international peace and security, develop friendly relations among nations and promote social progress, better living standards and human rights.

This material is produced independently for NTI by the James Martin Center for Nonproliferation Studies at the Middlebury Institute of International Studies at Monterey and does not necessarily reflect the opinions of and has not been independently verified by NTI or its directors, officers, employees, or agents. Copyright 2019.