The United Nations (UN) is the principal intergovernmental organization of the contemporary international order, established on 24 October 1945 when the UN Charter, signed at the San Francisco Conference on 26 June 1945 by 51 founding states, entered into force after ratification by the five permanent Security Council members and a majority of signatories. It superseded the failed League of Nations, and its name was coined by U.S. President Franklin D. Roosevelt in the "Declaration by United Nations" of 1 January 1942. The Charter's Preamble — drafted with input from Jan Smuts — opens "We the peoples of the United Nations," and Article 1 sets out the four core purposes: maintaining peace, developing friendly relations on the principle of equal rights and self-determination, achieving international cooperation, and serving as a center for harmonizing the actions of nations. As of 2026 the organization has 193 member states; its headquarters sits in New York City on land donated by John D. Rockefeller Jr.
The Charter establishes six principal organs. The General Assembly (Articles 9–22) is the plenary deliberative body where each state holds one vote, deciding important questions by two-thirds majority. The Security Council (Articles 23–32) bears "primary responsibility" for peace and security; its five permanent members — the United States, Russia (succeeding the USSR in 1991), the United Kingdom, France, and China — wield the veto under Article 27, alongside ten elected non-permanent members. Chapter VI governs pacific settlement of disputes, while Chapter VII authorizes enforcement action including sanctions (Article 41) and military force (Article 42). The Economic and Social Council (ECOSOC), the Trusteeship Council (suspended in 1994 after Palau's independence), the International Court of Justice at The Hague, and the Secretariat headed by the Secretary-General complete the structure. The "Uniting for Peace" resolution (Resolution 377, 1950) allowed the Assembly to act when the Council is deadlocked by veto.
Named milestones illustrate the UN's reach: the Universal Declaration of Human Rights (Resolution 217 A, 1948); peacekeeping operations beginning with UNTSO (1948) and the first armed force, UNEF, during the 1956 Suez Crisis; Resolution 181 (1947) partitioning Palestine; and Resolution 678 (1990) authorizing force against Iraq. The Secretary-General — António Guterres of Portugal serving his second term through 2026 — acts under Article 99 to bring threats to the Council's attention. Specialized agencies (WHO, UNESCO, ILO) and programmes (UNDP, UNICEF, UNHCR) form the wider UN system, and the Sustainable Development Goals (2015) guide its development agenda to 2030.
For the FSOT and UPSC alike, the UN is tested across U.S. foreign policy, world history, and international organization papers. FSOT candidates should master the U.S. role as host, largest financial contributor, and a P5 veto-holder, plus American history involvement from the 1945 Senate ratification (89–2) onward. Typical question angles include the veto mechanism and Article 27, the distinction between Chapter VI and Chapter VII action, the Uniting for Peace precedent, and the difference between binding Security Council resolutions and recommendatory General Assembly resolutions — a frequent trap. Reform debates over Security Council expansion (the G4 and Ezulwini Consensus) also recur.
Example
In 1990 the UN Security Council passed Resolution 678 authorizing member states to use "all necessary means" to expel Iraqi forces from Kuwait, providing the legal basis for the U.S.-led Gulf War coalition.
Frequently asked questions
The Security Council authorizes enforcement action, including military force, under Article 42 of Chapter VII. The General Assembly can only make non-binding recommendations, though the 1950 Uniting for Peace resolution created a limited exception when the Council is deadlocked.