History of NATO in Timeline

NATO is an intergovernmental military alliance founded in 1949, comprising 32 member states primarily from Europe and North America. It operates on the principle of collective security, meaning an attack on one member is considered an attack on all, as defined by Article 5 of the North Atlantic Treaty. Established post-World War II, its primary purpose is deterrence and defense against external threats.

1941: Atlantic Charter

In 1941, the Atlantic Charter, an agreement between the United States and United Kingdom, laid out a framework for international cooperation without territorial expansion after World War II, setting the stage for NATO's eventual formation.

March 1947: Treaty of Dunkirk Signed

On March 4, 1947, the Treaty of Dunkirk was signed by France and the United Kingdom as a Treaty of Alliance and Mutual Assistance in the event of possible attacks by Germany.

February 1948: Communist Coup in Czechoslovakia

In February 1948, the coup d'état in Czechoslovakia contributed to the promotion of international solidarity against perceived communist aggression, influencing the formation of NATO.

March 1948: Treaty of Brussels signed

In March 1948, the Treaty of Brussels expanded the alliance to include the Benelux countries, forming the Brussels Treaty Organization, also known as the Western Union.

April 1949: Establishment of NATO

On April 4, 1949, NATO was established with the signing of the North Atlantic Treaty (Washington Treaty) by its founding members.

April 1949: Signature of the North Atlantic Treaty

On April 4, 1949, the North Atlantic Treaty was signed by the member states of the Western Union, the United States, Canada, Portugal, Italy, Norway, Denmark, and Iceland.

1949: Establishment of NATO

In 1949, The North Atlantic Treaty Organization (NATO) was established with the signing of the North Atlantic Treaty. The organization serves as a system of collective security and deterrence.

1949: Original members joined NATO

In 1949, twelve countries became the original members of NATO.

1951: Formation of SHAPE

In 1951, Supreme Headquarters Allied Powers Europe (SHAPE) was formed, integrating military structures and plans.

1952: Greece and Turkey join NATO

In 1952, Greece and Turkey joined NATO.

1952: Establishment of Secretary General post and first NATO maritime exercises

In 1952, the post of Secretary General of NATO was established, and the first major NATO maritime exercises, Exercise Mainbrace, were held. Greece and Turkey also joined the organization in the same year.

May 1955: West Germany joins NATO

In May 1955, West Germany joined NATO, which was a major factor in the creation of the Soviet-dominated Warsaw Pact.

1955: West Germany joins NATO

In 1955, West Germany became a member of NATO.

1961: Building of the Berlin Wall

In 1961, the building of the Berlin Wall marked a height in Cold War tensions.

July 1962: Independence of French Algeria

On July 3, 1962, French Algeria gained independence, after which it was no longer covered by Article 5 of the North Atlantic Treaty.

1966: France withdraws from NATO's military structure

In 1966, France withdrew from NATO's military structure, while maintaining an independent nuclear deterrent.

1982: Treaty of Lisbon Article 42(7)

Article 42(7) of the 1982 Treaty of Lisbon specifies that "If a Member State is the victim of armed aggression on its territory, the other Member States shall have towards it an obligation of aid and assistance by all the means in their power".

1982: Spain joins NATO

In 1982, Spain joined NATO.

1989: Revolutions of 1989 in Europe

The Revolutions of 1989 in Europe led to a strategic re-evaluation of NATO's purpose and focus.

October 1990: East Germany becomes part of the Federal Republic of Germany

In October 1990, East Germany became part of the Federal Republic of Germany and the NATO alliance.

November 1990: Treaty on Conventional Armed Forces in Europe signed

In November 1990, the alliance signed the Treaty on Conventional Armed Forces in Europe (CFE) in Paris with the Soviet Union, mandating specific military reductions across the continent.

1990: Operation Anchor Guard

In 1990, NATO conducted its first military operation, Anchor Guard, prompted by the Iraqi invasion of Kuwait. Airborne early warning aircraft were sent to provide coverage of southeastern Turkey.

1990: East Germany added to NATO with reunification

In 1990, the territory of the former East Germany was added to NATO with the reunification of Germany.

1990: Beginning of political dialogue with Japan

Political dialogue with Japan began in 1990.

February 1991: Collapse of the Warsaw Pact

The Warsaw Pact collapsed in February 1991, removing the de facto main adversaries of NATO.

1991: Dissolution of the Soviet Union

Following the dissolution of the Soviet Union in 1991, NATO adapted its strategies and focus.

1991: Operation Ace Guard

In 1991, NATO conducted Operation Ace Guard, prompted by the Iraqi invasion of Kuwait. A quick-reaction force was deployed to southeastern Turkey.

October 1992: United Nations Security Council Resolution 816

In October 1992, the deteriorating situation in Bosnia led to United Nations Security Council Resolution 816, authorizing member states to enforce a previously declared no-fly zone.

1992: NATO intervention in Bosnian War

In 1992, NATO undertook its first military intervention in the Bosnian War, enforcing a no-fly zone and defending UN safe zones with a United Nations mandate.

1992: First Military Interventions in Bosnia

In 1992, during the breakup of Yugoslavia, NATO conducted its first military interventions in Bosnia.

April 1993: Operation Deny Flight begins

On 12 April 1993, NATO started enforcing the ban on flights over Bosnia and Herzegovina with Operation Deny Flight.

June 1993: Operation Sharp Guard begins

From June 1993, Operation Sharp Guard added maritime enforcement of the arms embargo and economic sanctions against the Federal Republic of Yugoslavia.

February 1994: NATO takes first wartime action

On 28 February 1994, NATO took its first wartime action by shooting down four Bosnian Serb aircraft violating the no-fly zone.

1994: Partnership for Peace and Mediterranean Dialogue initiative

In 1994, diplomatic forums for regional cooperation between NATO and its neighbours were set up, including the Partnership for Peace and the Mediterranean Dialogue initiative.

1994: Establishment of Partnership for Peace Programme

In 1994, the Partnership for Peace (PfP) programme was established, based on bilateral relations between each partner country and NATO.

1994: Establishment of Mediterranean Dialogue

The Mediterranean Dialogue was established in 1994 to coordinate with Israel and countries in North Africa.

1995: NATO Intervention in Bosnia Continues

From 1992 to 1995, NATO continued its first military interventions in Bosnia.

October 1996: Operation Sharp Guard ends

In October 1996, Operation Sharp Guard ended.

May 1997: Establishment of Euro-Atlantic Partnership Council

On 29 May 1997, the Euro-Atlantic Partnership Council (EAPC) was established as a forum for coordination, consultation, and dialogue between participants.

1997: Euro-Atlantic Partnership Council

In 1997, the Euro-Atlantic Partnership Council was established.

1998: Establishment of general guidelines for cooperation

In 1998, NATO established a set of general guidelines that do not allow for a formal institutionalization of relations, but reflect the Allies' desire to increase cooperation.

1998: NATO–Russia Permanent Joint Council

In 1998, the NATO–Russia Permanent Joint Council was established.

1999: Hungary, Poland, and the Czech Republic join NATO

At the 1999 Washington summit, Hungary, Poland, and the Czech Republic officially joined NATO.

1999: NATO intervention in Yugoslavia

In 1999, NATO intervened in Yugoslavia.

2000: Agreement on the term "Contact Countries"

Following extensive debate, the term "Contact Countries" was agreed by the Allies in 2000.

2001: Article 5 invoked after September 11 attacks

In 2001, Article 5 of the North Atlantic Treaty was invoked for the first time by the US after the September 11 attacks, leading to NATO involvement in Afghanistan as part of the International Security Assistance Force (ISAF).

December 2002: Signing of Berlin Plus agreement

On 16 December 2002, the European Union (EU) signed a comprehensive package of arrangements with NATO under the Berlin Plus agreement, giving the EU the possibility of using NATO assets.

2002: NATO-Ukraine Action Plan

In 2002, Ukraine's relationship with NATO began with the NATO–Ukraine Action Plan.

2004: Seven new members join NATO

In 2004, Bulgaria, Estonia, Latvia, Lithuania, Romania, Slovakia, and Slovenia joined NATO.

2004: Announcement of Istanbul Cooperation Initiative

The Istanbul Cooperation Initiative was announced in 2004 as a dialogue forum for the Middle East.

2005: Putin's statement on Ukraine joining NATO

In 2005, Russian president Vladimir Putin stated that Russia would respect Ukraine's choice if it joined NATO.

2006: Study on NATO enlargement and democratic consolidation

A 2006 study in the journal Security Studies argued that NATO enlargement contributed to democratic consolidation in Central and Eastern Europe.

2006: Goal for member states to spend 2% of GDP on defense

Since 2006, the goal has been for each NATO country to spend at least 2 percent of its gross domestic product on its own defense.

2007: Putin's Munich speech opposing NATO enlargement

Since his 2007 Munich speech, Vladimir Putin has strongly opposed further NATO enlargement.

2007: Election of Nicolas Sarkozy

The election of French president Nicolas Sarkozy in 2007 led to a major reform of France's military position.

2008: Georgia promised "future membership"

During the 2008 summit in Bucharest, Georgia was promised "future membership" in NATO.

April 2009: France returns to full NATO membership

On April 4, 2009, France returned to full NATO membership, rejoining the NATO Military Command Structure while maintaining an independent nuclear deterrent.

2009: Albania and Croatia join NATO

In 2009, Albania and Croatia became members of NATO.

2009: Return of France to NATO integrated military command

In 2009, Nicolas Sarkozy negotiated the return of France to NATO's integrated military command and the Defence Planning Committee.

2010: Ukraine reaffirms non-aligned status

In 2010, under President Viktor Yanukovych, Ukraine reaffirmed its non-aligned status and renounced aspirations of joining NATO.

2011: NATO intervention in Libyan civil war

In 2011, NATO intervened in the Libyan civil war, with a UN mandate to enforce a no-fly zone and protect civilians.

June 2012: Shooting down of Turkish military jet by Syria

In June 2012, a Turkish military jet was shot down by Syria, leading to Article 4 consultations within NATO.

October 2012: Syrian forces shelling Turkish cities

In October 2012, Syrian forces shelled Turkish cities, resulting in further Article 4 consultations within NATO.

2012: Broadening of the group of "global partners"

By 2012, NATO had broadened the group of "Contact Countries", which meets to discuss issues such as counter-piracy and technology exchange, under the names "global partners" or "partners across the globe".

December 2014: Ukraine ends non-aligned status

In December 2014, Ukraine's parliament voted to end its non-aligned status due to Russia's occupation of Crimea.

2014: Russian annexation of Crimea

Following the Russian annexation of Crimea in 2014, NATO suspended co-operation with Russia and deployed a tripwire force in the east.

2014: NATO involvement in Afghanistan ends

In 2014, NATO's involvement in Afghanistan as part of the International Security Assistance Force (ISAF) came to an end.

2014: Obama's statement on Georgia's NATO path

In 2014, US president Barack Obama stated that Georgia was not "currently on a path" to NATO membership.

2014: NATO declaration on defense spending

In 2014, a NATO declaration said that countries not meeting the 2% defense spending goal would "aim to move towards the 2 percent guideline within a decade".

2015: Military spending declines

From 1990 to 2015, military spending by NATO's European members declined by 28 percent.

2015: Suruç bombing

In 2015, Turkey attributed the Suruç bombing to ISIS and called for an emergency NATO meeting due to security issues along its southern border.

June 2016: Levada Center poll on NATO troop deployment threat

A June 2016 Levada Center poll found that 68 percent of Russians think that deploying NATO troops in the Baltic states and Poland is a threat to Russia.

2016: Creation of NATO Enhanced Forward Presence

At the 2016 Warsaw summit, NATO countries agreed on the creation of NATO Enhanced Forward Presence, which deployed four multinational battalion-sized battlegroups in Estonia, Latvia, Lithuania, and Poland.

2017: Montenegro joins NATO

In 2017, Montenegro joined NATO.

2017: Pew Research Center report on Russian threat perception in Poland

In a 2017 Pew Research Center report, 65 percent of Poles identified Russia as a "major threat".

January 2018: Qatar and NATO sign joint security agreement

In January 2018, Qatar and NATO signed a joint security agreement.

June 2018: Qatar expresses wish to join NATO

In June 2018, Qatar expressed a wish to join NATO, but it was ruled out.

2018: Poles favor US forces being based in Poland

In 2018, 67 percent of Poles surveyed favored US forces being based in Poland.

2019: Ukraine enshrines NATO membership goal in Constitution

In 2019, Ukraine enshrined the goal of NATO membership in the Constitution.

February 2020: Article 4 consultation due to Northwestern Syria offensive

In February 2020, another Article 4 consultation happened due to increasing tensions from the Northwestern Syria offensive, which involved airstrikes on Turkish troops and risked confrontation between Russia and a NATO member.

2020: North Macedonia joins NATO

In 2020, North Macedonia became a member of NATO.

June 2021: NATO leaders affirm Ukraine's eventual membership

At the June 2021 Brussels Summit, NATO leaders affirmed that Ukraine would eventually join and supported Ukraine's right to self-determination.

March 2022: Extraordinary NATO summit in Brussels

In March 2022, NATO leaders met at Brussels for an extraordinary summit. Member states agreed to establish four additional battlegroups in Bulgaria, Hungary, Romania, and Slovakia, and elements of the NATO Response Force were activated for the first time in NATO's history.

June 2022: NATO deploys troops along Eastern flank

As of June 2022, NATO had deployed 40,000 troops along its Eastern flank to deter Russian aggression. Spain sent Eurofighter Typhoons to supplement Bulgaria's Air Force, and the Netherlands sent eight F-35 attack aircraft.

July 2022: NATO estimate of members meeting the 2% target in 2023

In July 2022, NATO estimated that 11 members would meet the 2% defense spending target in 2023.

September 2022: Ukraine applies for NATO membership

In September 2022, Ukraine applied for NATO membership after Russia proclaimed it had annexed the country's southeast.

2022: Russian invasion of Ukraine

In 2022, the Russian invasion of Ukraine prompted NATO to reinforce its eastern flank and send military aid to Ukraine. Finland and Sweden also sought to join the alliance.

2023: NATO estimate of members meeting the 2% target in 2023

In 2023, NATO estimated that 11 members would meet the 2% defense spending target.

2023: Finland joins NATO

In 2023, spurred on by the Russo-Ukrainian war, Finland joined NATO.

2023: US and Germany biggest contributors

In 2023, the United States and Germany were the biggest contributors to the NATO budget at 16.2% each.

February 2024: Stoltenberg announces 18 members meeting 2% target in 2024

On 14 February 2024, NATO Secretary General Jens Stoltenberg said that 18 member states would meet the 2% defense spending target in 2024.

June 2024: Stoltenberg announces record 23 members meeting 2% target

On 17 June 2024, NATO Secretary General Jens Stoltenberg announced that a record 23 of 32 NATO member states were meeting their defense spending targets of 2% of their country's GDP.

2024: NATO commits to spending target

At the 2014 Wales summit, leaders of NATO's member states formally committed to spend at least two percent of their gross domestic products on defence by 2024.

2024: Sweden joins NATO

In 2024, spurred on by the Russo-Ukrainian war, Sweden became a member of NATO.

2024: US and Germany biggest contributors

In 2024, the United States and Germany were the biggest contributors to the NATO budget at 16.2% each.

2024: Rift between US and NATO members

Since 2024, NATO has faced an unprecedented rift between the United States and other members, as US president Donald Trump threatened the sovereignty of Canada and Denmark.

September 2025: Launch of Operation Eastern Sentry

In September 2025, Operation Eastern Sentry, a NATO military initiative, was launched in response to Russian drone incursions into Polish airspace.

2025: Germany stations armoured brigade in Lithuania

In 2025, Germany stationed a full armoured brigade in Lithuania.

2025: Internal crisis in NATO

Since 2025, NATO has faced internal crisis due to threats made by the United States against the sovereignty of fellow members Canada and Denmark.

March 2026: Trump calls NATO allies cowards

In March 2026, US president Donald Trump called NATO allies cowards for refusing calls to help reopen the Strait of Hormuz during the 2026 Israeli–United States strikes on Iran and described the alliance as ineffective without the U.S.