Finland and Sweden want to join NATO. Here’s how it works and what comes next

In Sweden on Sunday, Prime Minister Magdalena Andersson announced during a press conference her party’s support for the country to apply to join NATO.

The move must be approved by a vote in parliament in each country, but given the support of the ruling governments, that hurdle is expected to be passed comfortably.

“When we look at Russia, we see a very different kind of Russia today than we saw just a few months ago,” Finnish Prime Minister Sanna Marin said Sunday. “Everything has changed when Russia attacked Ukraine. And I personally think that we cannot trust anymore there will be a peaceful future next to Russia.”

Joining NATO is “an act of peace [so] that there will never again be war in Finland in the future,” Marin said.

Her Swedish counterpart, Andersson, said Sunday: “For us Social Democrats, the military non-alliance policy has served us well. But our analysis shows that it will not serve us as well in the future. This is not a decision that we have taken lightly.”

The announcements were met with support from leaders in almost all NATO nations. US Secretary of State Antony Blinken told reporters “the United States would strongly support the NATO application by either Sweden or Finland should they choose to formally apply to the alliance. We will respect whatever decision they make.”

What comes next?

NATO has what it calls an “open door policy” on new members — any European country can request to join, so long as they meet certain criteria and all existing members agree.

A country does not technically “apply” to join; Article 10 of its founding treaty states that, once a nation has expressed interest, the existing member states “may, by unanimous agreement, invite any other European State in a position to further the principles of this Treaty … to accede.”

NATO diplomats told Reuters that ratification of new members could take a year, as the legislatures of all 30 current members must approve new applicants.

The process may not be without hurdles; Turkey’s President Recep Tayyip Erdogan said Friday he was not looking at both countries joining NATO “positively,” accusing them of housing Kurdish “terrorist organizations.”

Finnish President Sauli Niinistö told CNN he was “confused” by those comments on Sunday, claiming Erdogan had been far more receptive to the idea in a telephone conversation between the two leaders a month ago.

“I think that what we need now is a very clear answer. I’m prepared to have a new discussion with President Erdogan about the problems he has raised,” Niinistö said.

But NATO Secretary General Jens Stoltenberg attempted to allay concerns about Turkey’s stance, saying Sunday the country “has made it clear that their intention is not to block membership.” Blinken also said Sunday he was “very confident that we will reach consensus.”

In the meantime, both countries will have to rely on its current allies and partners for security guarantees, rather than Article 5 — the clause which states an attack against one NATO nation is an attack against all, and which triggers a collective response in that event.

Sweden and Finland have received assurances of support from the United States and Germany should they come under attack, while British Prime Minister Boris Johnson signed mutual security agreements with his Finnish and Swedish counterparts last week.

What does NATO membership entail?

Article 5 has been a cornerstone of the alliance since NATO was founded in 1949 as a counterweight to the Soviet Union.

The point of the treaty, and Article 5 specifically, was to deter the Soviets from attacking liberal democracies that lacked military strength. Article 5 guarantees that the resources of the whole alliance — including the massive US military — can be used to protect any single member nation, such as smaller countries who would be…