U.S. Department of Defense
July 3, 2022

Nations Undergo Rigorous Process to Join NATO

Finland and Sweden filed letters of application to officially join The North Atlantic Treaty Organization on May 18, but joining NATO is not an overnight process.

State Department officials have said nations that want to enter NATO must meet five requirements:

New members must uphold democracy, which includes tolerating diversity.
New members must be in the midst of making progress toward a market economy.
The nations’ military forces must be under firm, civilian control.
The nations must be good neighbors and respect sovereignty outside their borders.
The nations must be working toward compatibility with NATO forces.


“All allies agree on the importance of NATO enlargement,” Stoltenberg told representatives of Finland and Sweden. “We all agree that this is an historic moment, which we must seize.”

After Russia invaded Ukraine in February, Swedish and Finnish officials said their countries wanted to join NATO and benefit from the organization’s collective defense strategy. Collective defense, outlined in Article 5 of NATO’s treaty, says “an attack on one member of the alliance is an attack on all.”


Thirty nations are NATO members: the United States, United Kingdom, Belgium, Canada, Denmark, France, Iceland, Italy, Luxembourg, Netherlands, Norway, Portugal, Albania, Lithuania, Bulgaria, Montenegro, Croatia, Czech Republic, Poland, Estonia, Romania, Germany, Slovakia, Greece, Slovenia, Hungary, Spain, Turkey, Latvia and North Macedonia.

Demonstrating NATO’s commitment to diversity. Photo: Pentagon.