Sweden will give up 200 years of neutrality and join neighboring Finland in applying to join NATO, a move that will change the geopolitics of Europe and have the huge unintended consequence of Vladimir Putin’s invasion of Ukraine.

On a big day for the Nordic countries, Finland’s president and prime minister said on Sunday they would apply to join NATO in the next few days, while Sweden’s ruling Social Democrats broke with tradition and said they would follow suit.

“This is a historic day. A new era has begun,” Finnish President Sauli Niinistö told a news conference as Putin’s brutal invasion of Ukraine, another non-NATO member that borders Russia, upended Helsinki Decades of Security Thinking.

Finnish Prime Minister Sanna Marin said: “We can no longer believe that there is a peaceful future next to Russia in our own power. That is why we made the decision to join NATO: it is a peace move to secure the future There is no more war in Finland.”

Announcing the decision, the Swedish Social Democrats said they would express reservations about the deployment of nuclear weapons in their application and the deployment of foreign bases on their soil. Finland said it would not impose any conditions.

Swedish Prime Minister Magdalena Andersson © Hannibal Hanschke / Getty Images

The entry of Finland and Sweden into NATO would be one of the most important and far-reaching consequences of Russia’s all-out war on Ukraine, a move that public opinion in these countries has massively supported since February.

Their potential addition would change the security situation in northern Europe and make it easier for the alliance to defend the Baltic states. It would also more than double the length of NATO’s border with Russia, which already threatens “serious military and political consequences” if either country joins the alliance.

A formal decision by the Finnish government on the application needs to be approved by parliament, which is due to meet on Monday. The Swedish government will also approve its application on Monday, paving the way for a possible joint submission of bids by its members during Niinistö’s state visit to Stockholm on Tuesday and Wednesday.

Both Niinisto and Marin played down concerns that Turkey could undermine Finland’s bid for NATO. Turkish President Recep Tayyip Erdoğan said on Friday he could not be “positive” about potential membership applications from Finland and Sweden.

Niinisto said he was “a little confused” during a conversation with Erdogan in April, in which the Turkish president told him: “We will evaluate it positively.”

Erdogan cited Sweden and Finland’s support for the Kurdistan Workers’ Party (PKK), which has waged a decades-long armed rebellion against the Turkish state, as a reason for his opposition. It is listed as a terrorist organization by Ankara, the United States and the European Union. Erdogan said the Scandinavian country was “like some kind of guest house for terrorist groups”.

But Turkey appears to be the only country to take that stance, with most NATO members expressing strong support for Finland and Sweden to join.

NATO Secretary General Jens Stoltenberg said he was confident Turkey’s position would not pose an insurmountable obstacle. “Turkey has made it clear that its intention is not to prevent Finland and Sweden from joining NATO,” he told reporters via video link.

Speaking after an informal meeting of NATO foreign ministers in Berlin, he said he was “confident that we will be able to address the concerns expressed by Turkey in a way that does not delay the accession or accession process”.

Stoltenberg added that during the transition period, NATO will “study ways to provide security assurances, including increasing NATO’s presence in and around the Baltic region, Finland and Sweden”.

U.S. Secretary of State Anthony Blinken said he had spoken with Turkey’s foreign minister about Ankara’s concerns, and after Sunday’s meeting of foreign ministers, he believed a consensus could be reached.

“I don’t want to describe the specific conversations we had with the foreign minister or with the NATO meeting itself, but I can say this: I heard very strong support almost across the board. [for Sweden and Finland] Join the league,” he said.

NATO foreign ministers on Sunday discussed the war in Ukraine and how they can step up aid to the authorities in Kyiv. They also talked about NATO’s new strategic concept ahead of the NATO summit in Madrid in June.

This will identify the security challenges NATO faces and outline the political and military missions it will undertake to address them.

German Foreign Minister Annalena Berbock said there should be no delay in bringing Sweden and Finland into NATO. “There should be no . . . grey areas,” she said ahead of Sunday’s consultation. “It can’t be a long process.”

Many countries never thought about joining a defense treaty, “but now they’re being pushed into NATO by Russia’s war of aggression in Ukraine,” Belbok said.