The UN at 80: An overview of the United Nations

This briefing is part of the “UN at 80” series of short briefings from the House of Commons Library, taking stock of the 80-year existence of the United Nations, and looking ahead to what might be in store for the UN in the future.

The UN at 80: An overview of the United Nations History and Overview

The United Nations (UN) Charter was signed on 26 June 1945 in San Francisco, United States. It came into force on 24 October 1945.

Since 1945, the UN has grown beyond the United Nations Organisation into a wider system of programmes, specialised agencies, and other international bodies (PDF).

The wider UN System includes international agencies such as the World Health Organisation, International Monetary Fund, and certain bodies of the World Bank Group, whose activities are coordinated alongside the UN. A chart produced by the UN (PDF) outlines the wider UN system and its multiple agencies, while summaries of each of the agencies and their work is available on the UN System page of the UN website.

While one of the main focuses of the UN, according to its Charter, is the maintenance of international peace and security, the UN’s work has expanded in recent years to tackle new global challenges. As well as setting up numerous bodies to monitor international human rights, the UN has also adopted special focuses on sustainable development, and tackling climate change.

Purposes of the United Nations

The preamble of the Charter of the United Nations refers to the motivations behind the establishment of the UN as being:

• to save succeeding generations from the scourge of war;
• to reaffirm faith in fundamental human rights;
• to establish conditions for the respect of international legal obligations, and;
• to promote social progress and better standards of life.

Moreover, Article 1 of the UN Charter also lists the purposes of the United Nations, which include:

• The maintenance of international peace and security;
• The settlement of international disputes, or threats to international peace;
• Strengthening universal peace based on friendly relations between states and respect for equal rights and self-determination;
• International cooperation in economic, social, cultural, and humanitarian issues;
• Encouraging respect for human rights and fundamental freedoms;
• To be a centre for harmonising the actions of nations for these purposes.

The Purposes of the UN must also be read in conjunction with the Principles of the UN in Article 2, which includes principles such as the prohibition of force, or the requirement to settle disputes peacefully.

Founding Members

Fifty nations officially signed the United Nations Charter on June 26, 1945. Poland, though not present at the initial signing, became the 51st founding member on October 15, 1945. The term "founding members" refers to all countries invited to the 1945 San Francisco Conference, where the UN Charter and the Statute of the International Court of Justice (ICJ) were adopted.

Five members (often referred to as the P5), hold permanent seats within the UN’s Security Council – the decision-making body for issues on international peace and security. These five members were seen as reflecting the “great powers” of the world following World War II:

• China
• France
• Russia
• UK
• US

The other 10 non-permanent members of the Council are elected by the General Assembly for two-year terms, with five elected each year.

Key historical events and people leading to the UN

In August 1941, Winston Churchill and US President Franklin D Roosevelt signed the Atlantic Charter, which referred to the future “establishment of a wider and permanent system of general security”.

In January 1942, 26 states signed the “Declaration by United Nations”, which subscribed to the purposes and principles of the Atlantic Charter, and joined states together against the Axis during WWII. It marked the first time the term “United Nations” was used in an official international document, and was coined by US President Roosevelt.

In 1943, Conferences in Moscow and Tehran bringing together the US, UK, USSR, and China (in Moscow only), reiterated efforts to establish a system of international peace and security once the second world war was over. The Moscow Conference in 1943 in particular adopted a Joint Four-Nation Declaration in which they “recognize[d] the necessity of establishing at the earliest practicable date a general international organization, based on the principle of the sovereign equality of all peace-loving States, and open to membership by all such States, large and small, for the maintenance of international peace and security”.

In 1944, the US and UK met the USSR and Chinese representatives as part of the Dumbarton Oaks Conference (also known as the “Washington Conversations on International Peace and Security Organization”). Here, the initial working document, the skeleton draft of what became the UN Charter, came out of negotiations between the states. In 1945, some months prior to the main San Francisco conference on the drafting of the Charter, President Roosevelt, Prime Minister Churchill and Premier Stalin, met at the Yalta Conference which decided on the nations to be invited to San Francisco, and also on the “Yalta Formula” – the voting procedure at the UN Security Council, where each permanent member of the Council was granted a veto over substantive decisions.

In April 1945, US President Roosevelt died before he could host the San Francisco conference as arranged, but US President Truman continued with his plans.

First sessions of the UN in London

To facilitate the establishment of a permanent home and other aspects of the UN as an organisation, the UN had a preparatory commission based in London. This commission decided to host the first meetings of the General Assembly and the Security Council on the 10 and 17 of January 1946 respectively. FCDO historian Richard Smith highlights that these efforts were led by British diplomat Gladwyn Jebb, assistant David Owen, and Brian Urquhart. The Security Council was hosted in Church House, while the Methodist Central Hall hosted the General Assembly – with the General Assembly sessions continuing for more than a month.

Organs and Powers of the United Nations

The UN has six main organs that were established under the UN Charter:

The General Assembly

The General Assembly is the main forum within the UN where all 193 Member States are represented. The Assembly has the function of being the main forum for States to discuss, deliberate, and construct policies on any of the issues that fall within the UN Charter. The General Assembly is based at the UN Headquarters in New York, US.

The Security Council

The Security Council has primary responsibility for the maintenance of international peace and security, and is tasked with responding to threats to peace, breaches of the peace, or acts of aggression. It also has responsibility to help solve international disputes that could endanger international peace. The Security Council is based at the UN Headquarters in New York, US.

The Economic and Social Council

The Economic and Social Council coordinates and reviews international policy on economic, social and environmental issues. It is responsible for overseeing the implementation of international development goals. It is located at the UN Headquarters in New York, US, but also holds sessions in Geneva, Switzerland.

The Trusteeship Council

The Trusteeship Council originally oversaw the transition to self-governance and independence of 11 Trust Territories. By 1994, all 11 Territories gained self-governing or independent status, and so the Trusteeship Council was suspended in November 1994.

The International Court of Justice

The International Court of Justice (ICJ) is the judicial organ of the United Nations, which hears disputes (contentious cases) between states, or interprets issues of international law and the UN Charter in Advisory Opinions. The ICJ is located in The Hague, Netherlands, at the Peace Palace. The Peace Palace also hosts other institutions such as the Permanent Court of Arbitration.

The Secretariat

The Secretariat is like the UN’s civil service, overseeing the day-to-day running of the UN, led by the UN Secretary-General.

The General Assembly, Security Council, and Economic and Social Council have established numerous subsidiary organs to carry out more specialised elements of their work. The UN Secretariat has also established several sub-departments and offices such as the Office of the High Commissioner for Human Rights, the United Nations Office on Drugs and Crime, and the UN’s Office of Legal Affairs.

Reflections on the UN at 80

In 2023, the Secretary-General of the United Nations launched a policy brief entitled A New Agenda For Peace, aimed at re-invigorating international cooperation for peace and security, moving away from competition between Member States and instead enhancing cooperation and collective action for achieving shared interests. This was adopted in the run-up to the Summit of the Future in 2024, where the UN also adopted a new Pact for the Future, aimed at bolstering multilateral cooperation at the United Nations for numerous issues, including international peace and security, but also in strengthening the role of the UN in other areas.

The Pact for the Future was described by the UN as:

… the culmination of an inclusive, years-long process to adapt international cooperation to the realities of today and the challenges of tomorrow. The most wide-ranging international agreement in many years, covering entirely new areas as well as issues on which agreement has not been possible in decades, the Pact aims above all to ensure that international institutions can deliver in the face of a world that has changed dramatically since they were created. As the Secretary-General has said: “We cannot create a future fit for our grandchildren with a system built by our grandparents.”

On 24 October 2025, the UN Security Council met to debate the future of the United Nations on its 80th anniversary. While its 15 Members shared the view that there was a need to uphold the core principles of the UN Charter, there were clear divides between states on whether some truly upheld those norms.

The Council agreed on a presidential statement, introduced by Russia, that reaffirmed the Council’s commitment to the UN Charter, the central role of the UN in international affairs, and to “an international order based on international law”. The statement considered that this is:

… the indispensable foundation of a more peaceful, prosperous and just world for cooperation among States in preventing and addressing threats to international peace and security.

Russia, president of the Council for October 2025, accused “the West” of dividing the world into “us” and “them”, and suggesting that the UN Charter’s principles remain only written on paper, rather than being upheld. The UK representative accused Russia of hypocrisy in “positioning itself as a champion of the Charter”, accusing Russia of “flagrantly contravening the prohibition on the use of force against the territorial integrity of another State” in reference to Russia’s invasion of Ukraine. The UK warned that this undermines the role of the Security Council itself:

This makes a mockery of the very platform we have been given in the Security Council to uphold international law and to maintain peace and security.

The US representative believed that the UN has “lost its way”, blaming inefficiencies, excessive spending and believing that there were “divisive ideologies that undermine sovereignty.” As the UN’s largest financial contributor, the US said it expects “a strong return on our investment.”

Many states supported the principle of reforming the UN, and the UK supported specific principles in reforming the UN Security Council itself:

The UK also believes that the Security Council should be reformed to make it more representative of the world today. We support reforms to both permanent and non-permanent membership. This includes permanent membership for Africa, plus permanent seats for Germany, Japan, India and Brazil.

At the same meeting, the UN Secretary-General António Guterres stressed the need for reform, and warned that the UN’s legitimacy is fragile, with states too often acting outside of the UN Charter, eroding faith in the organisation, and setting dangerous precedents for others to follow.

Further reading and commentary

• Commons Library Briefing Series: The United Nations at 80
• The United Nations at 80, UN Information Service Vienna
• Richard Gowan, “At 80, the UN struggles on”, Le Monde, October 2025
• Natalie Samarasinghe and Savita Pawnday, “At 80, the UN must hold the line on protection”, GCR2P, 11 August 2025
• Devika Hovell, “The UN Charter at 80”, EJIL Talk!, 24 October 2025
• Mariel Ferragamo and Diana Roy, “The UN80 Initiative: What to Know About the United Nations’ Reform Plan”, Council on Foreign Relations, 15 September 2025