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Home : News : News
NEWS | June 6, 2022

Nations undergo rigorous process to join NATO

By Terri Moon Cronk DOD News

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.

Two applications sit on a table.
NATO Applications
NATO Secretary General Jens Stoltenberg receives official letters of application to join NATO from Klaus Korhonen, ambassador of Finland accredited to NATO, and Axel Wernhoff, ambassador of Sweden accredited to NATO, in Brussels, May 18, 2022.
Photo By: NATO
VIRIN: 220518-O-D0439-102R

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.

Blue flag with NATO emblem waves
NATO flag
NATO flag
Photo By: NATO
VIRIN: 220316-O-D0439-101R

Finland and Sweden meet the majority of requirements to enter NATO economically, governmentally and militarily, but new members must be invited by a consensus of existing NATO members, State Department officials said. 

State Department officials said a key determining factor for any invitation to new members is whether their admission to NATO will strengthen the alliance and further the basic objective of NATO enlargement, which is to increase security and stability across Europe. 

Soldiers in a kneeling position fire a shoulder-mounted missile weapon while three other soldiers observe in the background.
Live Fire
Army paratroopers assigned to the 173rd Airborne Brigade fire an FIM-92 Stinger short-range air-defense surface-to-air missile system during a live-fire exercise alongside soldiers with the Croatian Air Defense Regiment at Kamenjak near Medulin, Croatia, April 8, 2022. This training is part of Exercise Shield 22, an annual joint training on air-defense tactics, techniques and procedures for air-space control, deconfliction and surveillance, and targeting and live-fire engagement against flying objects at low and medium altitudes.
Photo By: Army Staff Sgt. John Yountz
VIRIN: 220409-A-TO756-403

The process is overseen by the North Atlantic Council, which is NATO's governing body. 

"All allies agree on the importance of NATO enlargement," Stoltenberg told representatives of Finland and Sweden. "We all agree that this is a 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." 

When both nations filed applications, NATO Secretary-General Jens Stoltenberg welcomed their requests, saying the countries are NATO's closest partners. "Your membership in NATO would increase our shared security," he said. 

"Allies will now consider the next steps on your path to NATO. The security interests of all allies have to be taken into account, and we are determined to work through all issues and reach rapid conclusions," Stoltenberg said. 

A man sits at a desk and speaks into a microphone.
Jens Stoltenberg
NATO Secretary General Jens Stoltenberg opens a session during the meeting of defense ministers at NATO Headquarters in Brussels, Feb. 12, 2020. The North Atlantic Council meets periodically throughout the year at different levels of governance and coordination; the event brings together defense ministers from all NATO allies to discuss the future of the alliance.
Photo By: Air Force Tech. Sgt. Cody H. Ramirez, NATO
VIRIN: 200212-F-WE773-001

Created in 1949 as a military alliance following World War II, NATO rests on the "collective defense" principle. It guarantees the freedom and security of member nations through political and military means, according to the NATO website

Politically, NATO promotes democratic values and enables members to consult and cooperate to solve defense and security-related issues, build trust and prevent conflict, according to the organization's website. Militarily,  NATO is committed to the peaceful resolution of disputes. If diplomatic efforts fail, it has the military power to undertake crisis-management operations. 

Military power is carried out under the collective defense clause of NATO's founding treaty — Article 5 of the Washington Treaty — or under a United Nations mandate. This can be done alone or in cooperation with other countries and international organizations, according to NATO's website. 

The flags of NATO members blow in the wind.
NATO Flags
The flags of NATO members fly in front of the organization's headquarters in Brussels.
Photo By: NATO photo
VIRIN: 210216-O-ZZ999-001

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.