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North Atlantic Treaty Organization
References & Edit History Quick Facts & Related Topics
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Flag of NATO featuring a white compass rose emblem with four lines radiating from the center on a blue background. World map highlighting NATO member countries in dark blue, Euro-Atlantic Partnership Council countries in light blue, NATO's Mediterranean Dialogue partners in purple, Istanbul Cooperation Initiative partners in pink, and global partners in teal. Brussels, Belgium, is marked as NATO headquarters. A timeline below the map shows the years each member joined NATO from 1949 to 2024. Secretary of State Dean Acheson sits at a table signing the North Atlantic Pact as President Harry Truman and Vice President Alben Barkley stand behind him, with officials observing. Member states of NATO Map of Europe in 1960 during the Cold War, showing countries color-coded by political alignment: NATO members in green across Western Europe, Warsaw Pact countries in orange in Eastern Europe, and non-aligned nations in beige. The Soviet Union and its allies are grouped to the east, while Western European countries are aligned with the United States. Kosovo conflict flag-raising ceremony marking the accession of the Czech Republic, Hungary, and Poland to NATO Jerzy Buzek, Miloš Zeman, Javier Solana, and Viktor Orbán at a ceremony marking the accession of the Czech Republic, Hungary, and Poland to NATO Volodymyr Zelensky during the Russian invasion of Ukraine Swedish Prime Minister Magdalena Andersson in a blue coat stands beside Finnish Prime Minister Sanna Marin in a black jacket outdoors before a meeting in Stockholm.
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NATO summary
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North Atlantic Treaty Organization: References & Edit History

Additional Reading

Don Cook, Forging the Alliance: NATO, 1945–50 (1989), examines the founding of NATO. Discussions of the development of NATO after the Cold War can be found in Sten Rynning, NATO Renewed: The Power and Purpose of Transatlantic Cooperation (2005); David S. Yost, NATO Transformed: The Alliance’s New Roles in International Security (1998); David G. Haglund (ed.), New NATO, New Century: Canada, the United States, and the Future of the Atlantic Alliance (2000); Martin A. Smith and Graham Timmins, Building a Bigger Europe: EU and NATO Enlargement in Comparative Perspective (2000); and Anton A. Bebler (ed.), The Challenge of NATO Enlargement (1999). Nuclear issues are explored in David N. Schwartz, NATO’s Nuclear Dilemmas (1983). NATO regularly publishes helpful source material in North Atlantic Treaty Organization, The NATO Handbook (annual).

Article Contributors

Primary Contributors

  • David G. Haglund
  • The Editors of Encyclopaedia Britannica
    Encyclopaedia Britannica's editors oversee subject areas in which they have extensive knowledge, whether from years of experience gained by working on that content or via study for an advanced degree. They write new content and verify and edit content received from contributors.

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Article History

Type Description Contributor Date
Modified link of Web site: North Atlantic Treaty Organization - Kosovo Air Campaign (March-June 1999). May 28, 2026
Top Question added. Apr 01, 2026
Top Question added. Jan 14, 2026
Questions and answers revised. Sep 10, 2025
Added link to article on how countries join NATO. Jul 17, 2025
Revised the Top Questions section. Jun 25, 2025
Revised Top Questions section. Jun 23, 2025
Revised Top Questions section. Jun 22, 2025
Questions and answers added. Jan 17, 2025
Migration of Accordions to article. Dec 09, 2024
Dataset of NATO member states added, and article revised. May 24, 2024
Add new Web site: Khan Academy - Start of the Cold War - The Berlin airlift and the creation of NATO. May 09, 2024
Noted Sweden's accession to NATO. Mar 07, 2024
Article updated for the accession of Finland to NATO. Apr 05, 2023
Corrected display issue. Mar 20, 2023
Added discussion of the Bucharest Nine. Feb 17, 2023
Add new Web site: Council on Foreign Relations - What Is NATO? Dec 01, 2022
Add new Web site: Academia - North Atlantic Treaty Organization and Management of the Ukrainian Crisis. Aug 23, 2022
Revised opening paragraph. Jul 05, 2022
Updated for the invitation of Finland and Sweden to join NATO. Jun 30, 2022
Add new Web site: The Balance - What is NATO? Mar 07, 2022
Corrected display issue. Mar 01, 2022
Noted that North Macedonia became a member. Mar 18, 2021
Article revised and updated. Jan 30, 2020
Add new Web site: GlobalSecurity.org - North Atlantic Treaty Organization. Oct 04, 2017
Updated for Montenegro's admission to the alliance. Jun 08, 2017
Add new Web site: Nuclear Threat Initiative - Treaties and Regimes - North Atlantic Treaty Organization. Dec 01, 2016
Add new Web site: The Canadian Encyclopedia - North Atlantic Treaty Organization. Apr 16, 2014
Add new Web site: The Cold War Museum - North Atlantic Treaty Organization. Apr 16, 2014
Add new Web site: North Atlantic Treaty Organization - Kosovo Air Campaign (March-June 1999). Nov 25, 2013
Add new Web site: The Canadian Encyclopedia - North Atlantic Treaty Organization. Dec 28, 2012
Add new Web site: U.S. Department of State - Office of the Historian - North Atlantic Treaty Organization. Dec 17, 2012
Add new Web site: Council on Foreign Relations - The North Atlantic Treaty Organization. Dec 14, 2012
Add new Web site: Spartacus Educational - North Atlantic Treaty Organization. Dec 14, 2012
Add new Web site: The Canadian Encyclopedia - North Atlantic Treaty Organization. Dec 14, 2012
Add new Web site: The Canadian Encyclopedia - North Atlantic Treaty Organization. Dec 14, 2012
Bibliography revised and updated. Jun 20, 2012
Article revised and updated. Jun 05, 2012
Image of the NATO flag added. May 18, 2012
Map of NATO members and partners added. May 15, 2012
Changed "The Netherlands" to "the Netherlands." May 19, 2010
Updated with Albania and Croatia acceding to the alliance. Apr 02, 2009
Updated introduction with France's announced plan to rejoin NATO's integrated military command. Mar 12, 2009
New images added. Jan 29, 2009
Added new Web site: How Stuff Works - People - How NATO Works. Dec 23, 2008
Media added. Mar 10, 2008
Added new Web site: BBC News - North Atlantic Treaty Organization. Jan 03, 2008
Added new Web site: Official Site of North Atlantic Treaty Organization. Jan 03, 2008
Article revised. Mar 12, 2004
Article revised. Sep 18, 2003
Article revised. Apr 19, 2002
Article revised. Dec 21, 2001
Article revised. Nov 02, 2001
Article revised. Dec 07, 1999
Article added to new online database. Jul 20, 1998
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