The formal decision was made on Sunday and requires sign-off by the parliament, President Sauli Niinisto said at a press conference in Helsinki. It comes just days after Niinisto and Prime Minister Sanna Marin said the Nordic country “must apply for NATO membership without delay.”

“When we look at Russia, we see a very different kind of Russia today than we saw just a few months ago,” Marin told reporters in Helsinki. “We cannot trust anymore that there will be a peaceful future next to Russia on our own.”

“That’s why we’re making the decision to join NATO,” she said. “It’s an act of peace so that there would never again be war in Finland.”

Finland was driven into the fold of the North Atlantic Treaty Organization by Russia’s Feb. 24 invasion of Ukraine, and is pulling neighboring Sweden along, with a decision by the ruling party in that country slated for later on Sunday in Stockholm. The attack shifted popular opinion overnight, with policy makers rapidly kicking off the process to join.

“We have been talking here in Finland for at least 30 years about NATO membership,” Niinisto said. “When we talk about security, even if it’s not that visible in daily life, it has huge impact in our minds and that makes this decision also historic.”

The move—which has a wide backing among lawmakers in Helsinki—has been called the third defining moment in Finnish history, completing the Nordic nation’s century-long aspiration to be considered a fully fledged part of the west.

Having won independence in 1917 after more than 100 years as a Grand Duchy of the Russian Empire, Finns fought two wars with the Soviet Union, ceding parts of their territory in 1944. Finland then tiptoed through an era of neutrality during the Cold War — by necessity, not by choice—cowering to Moscow while retaining independence in a policy that came to be known as Finlandization.

After the collapse of the Soviet Union, the Nordic country immediately sought entry into the European fold in Sweden’s wake, with the two joining the European Union in 1995.

The move to join NATO “is an absolutely monumental change politically, in those countries, because they’ve had the opportunity now for three decades to join NATO, and Sweden for even longer than that, but chose to remain outside,” Elisabeth Braw, senior fellow at the American Enterprise Institute, said by phone before the decision. “This is really an extraordinary step and a huge development, politically.”

Survival

A former president, Mauno Koivisto, was once asked what the idea of Finland is, if not a part of Russia. His famous one-word reply: “Survival.”

In that spirit, the country of 5.5 million people has always remained on alert. It’s guarding a border roughly 800 miles long, has a reserve of 900,000 troops and is able to deploy 280,000 of them in war time. It’s held on to a conscription-based system where most men and some women undergo military training lasting from six months to a year. 

Finland’s military equipment are compatible with NATO gear and include a large number of artillery and tanks. The country in December decided to buy 64 Lockheed Martin Corp. F-35A multi-role fighter jets to replace its aging F/A-18 Hornets in a $10.4 billion procurement.

Neighboring Sweden’s ruling Social Democrats are on Sunday planning to disclose their stance on NATO membership, just as policy makers are seeking to calm concerns that Turkey could derail their bid, citing concerns over Kurdish “terrorists.” Niinisto said Turkey’s President Recep Tayyip Erdogan had said about a month ago that he would assess Finland’s NATO application “favorably,” and so “you can understand I am a bit confused.”

Niinisto urged “a clear answer” from Erdogan and said that he was prepared to meet to discuss the issues raised. The Nordic countries were met with widespread support by NATO foreign ministers gathering in Berlin on Saturday and Secretary General Jens Stoltenberg has repeatedly said the two would be warmly welcomed. The military bloc requires unanimity to bring in new members.

According to a recent survey, 84% of Finns think that Russia poses a significant military threat, and they’re nearly unanimous in saying their neighbor is “unstable and unpredictable” with just 2% rejecting that characterization of Russia. Policy makers say there’s no immediate threat.

Russian reaction

President Niinisto phoned Russian President Vladimir Putin on Saturday to say the Nordic country plans to seek NATO membership. The move would be a “mistake because there are no threats to Finland’s security,” Putin told his Finnish counterpart, according to a statement from the Kremlin, adding that it could harm relations between the countries.

Putin’s reaction to the Finnish plan was “milder than ever before,” Niinisto told reporters on Sunday. “It may be that they want to avoid” this becoming a topic of discussion in Russia, he said.

Russia has hinted at the prospect of more troops on the border, or bringing nuclear weapons into its Baltic exclave of Kaliningrad in response.

“This is a card the Russians have been playing since 2014 and onward,” said Anna Wieslander, director for Northern Europe at the Atlantic Council. “We believe that they have had such weapons in Kaliningrad already since 2018 and have taken precautions due to that.”(Updates with comments from Marin, Niinisto from third paragraph)

With assistance from Chris Miller and Ott Tammik.