NATO open door policy

The NATO open door policy began in April 1999. It is part of NATO’s plan to grow bigger and stronger.

Any country can ask to join NATO, but all current NATO members must agree first.

The open door policy helps make sure every country that wants to join gets a fair chance. It also helps bring more teamwork between countries. By letting new members join, NATO aims to create a safer world where friends work together to solve problems and protect peace.

History

Post-Cold War enlargement of NATO

After big changes in Eastern Europe in 1989, many countries that were once part of a group called the Eastern Bloc wanted to join NATO. In March 1992, a top NATO leader said that NATO's "doors are open" to new members. In December 1994, the United States and NATO allies said that no European country should be stopped from joining.

In March 1999, Poland, Hungary, and the Czech Republic became the first former Eastern Bloc countries to join NATO. Later, in March 2004, Estonia, Latvia, Lithuania, Bulgaria, Romania, Slovakia, and Slovenia joined too. A leader from the United States said that NATO's door would stay open until all of Europe was united in freedom and peace.

In April 2008, NATO again said that any European country that wanted to join and could meet certain requirements could become a member. Ukraine was invited to join at that time.

In December 2015, Montenegro was invited to join NATO, and Georgia was encouraged to keep working toward membership. NATO leaders said they would keep supporting partners who wanted to join.

In November 2020, NATO talked about bringing back its open door policy, including helping Georgia join. In February 2021, Ukraine's leader said he hoped Ukraine could get a plan to join NATO soon. NATO confirmed that Ukraine is a candidate to join.

In June 2021, NATO again said it would keep its open door policy and reminded everyone that Georgia and Ukraine were expected to become members.

Russian invasion of Ukraine

Because of worries about safety, NATO said it would keep its promise that any country could choose to join, even after a big fight started in Ukraine in February 2022. Leaders from NATO countries said each nation has the right to choose its own security, and they would keep supporting Ukraine.

In May 2022, Turkey said it supported NATO's open door policy but did not want Finland and Sweden to join because of concerns about safety. Later, in June 2022, Finland, Sweden, and Turkey signed an agreement that allowed Finland and Sweden to start joining NATO. Finland joined in April 2023, and Sweden joined in March 2024.