Level 8 of 10: The UN and global treaty bodies

NATO

NATO is an alliance of 32 countries in Europe and North America, created by the North Atlantic Treaty of 4 April 1949. Under Article 5 an armed attack on one member is treated as an attack on all; NATO says every decision is taken by consensus, with no voting, starting with the North Atlantic Council where each member has a representative. The UK was one of the 12 founding members.

Who leads it

• Secretary General: Mark Rutte (since 1 October 2024) (nato.int)

The UK and the NATO

NATO lists the United Kingdom among its 12 founding members, which signed the North Atlantic Treaty in Washington, D.C. on 4 April 1949. NATO estimates UK defence spending at 2.40% of GDP in 2025.

Key figures

What it decides

• Collective defence: an armed attack against one or more members in Europe or North America is considered an attack against them all, and each will assist using the right of self-defence in Article 51 of the UN Charter (North Atlantic Treaty, Article 5).
• Members keep and develop their individual and collective capacity to resist armed attack (Article 3).
• Membership is open by invitation to any European state able to further the Treaty's principles (Article 10).
• The North Atlantic Council is NATO's principal political decision-making body, chaired by the Secretary General; decisions are by unanimity and common accord, with no voting.
• Allies collectively decide what is eligible for common funding and how much can be spent each year, using a cost-share formula based on Gross National Income.

Records you can check

• Defence Expenditure of NATO Countries (2014-2025)
  Each Ally's defence spending in cash and as a share of GDP, by year
• Funding NATO
  How NATO's common budgets are funded and governed
• The North Atlantic Treaty
  The full text of the 1949 treaty, including Article 5

Common questions

How many countries are in NATO?

32. NATO says it has 32 member countries, called Allies.

What is NATO Article 5?

Article 5 of the North Atlantic Treaty says an armed attack against one member is considered an attack against all. NATO says it has been invoked once, after the 9/11 attacks in 2001.

How much does the UK spend on defence according to NATO?

NATO estimates UK defence spending at 2.40% of GDP in 2025, or £70,196 million at current prices.

What is NATO's 5% target?

NATO says that at the 2025 Hague Summit Allies committed to invest 5% of GDP a year on defence by 2035, including at least 3.5% on core defence requirements and up to 1.5% on wider defence- and security-related spending.

Who is the head of NATO?

Mark Rutte. NATO says he became its 14th Secretary General on 1 October 2024.

Does NATO vote on decisions?

No. NATO says consensus has been the sole basis for decision-making since 1949; consultations continue until a decision acceptable to all is reached.

Other bodies at level 8

• Commonwealth of Nations
• International Court of Justice
• International Criminal Court
• International Labour Organization
• Interpol
• UN High Commissioner for Refugees (UNHCR)
• United Nations (General Assembly and Security Council)
• United Nations Children's Fund
• United Nations Educational, Scientific and Cultural Organization
• United Nations Human Rights Council
• United Nations Security Council
• World Food Programme
• World Health Organization
• World Trade Organization

Sources

• NATO member countries, read 16 October 2026
• Mark Rutte | NATO Secretary General, read 20 October 2026
• Funding NATO, read 20 October 2026
• Defence investment and NATO's 5% commitment, read 20 October 2026
• Consensus decision-making at NATO, read 20 October 2026
• North Atlantic Council (NAC), read 20 October 2026
• Collective defence and Article 5, read 20 October 2026
• The North Atlantic Treaty, read 20 October 2026
• Defence Expenditure of NATO Countries (2014-2025), read 20 October 2026