Turkish parliament on Thursday voted unanimously to ratify Finland’s entry into the North Atlantic Treaty Organization, paving the way for Russia’s Nordic neighbor to become the alliance’s 31st member.

The move marks a major reversal for Finland and Sweden, both of which sought NATO membership after Russia invaded Ukraine a year ago. It also marks a sea change for NATO, insofar as Finland guards a border with Russia roughly 1,300 kilometers (800 miles) long.

“NATO now has to enhance the military planning to this region,” Finnish Foreign Affairs Minister Pekka Haavisto said in a Bloomberg TV interview. “NATO will take out possible risks for Finland but we also underline that we have a very strong military.”

Following the vote, NATO Secretary General Jens Stoltenberg wrote on Twitter that he welcomed the result and that the ratification would make the “NATO family stronger and safer.”

Both Turkey and Hungary signaled earlier this month they’d approve Finland’s solo entry following months of stonewalling, decoupling the two Nordic nations’ bids even after both were invited last June to start accession proceedings. Turkish President Recep Tayyip Erdogan accuses Sweden of not doing enough to crack down on groups that Turkey labels as terrorist, while the party of Hungarian Prime Minister Viktor Orban has linked that country’s veto to a clash inside the European Union over the rule of law.

Finland and Sweden have both already started integrating into the alliance and have been involved in all NATO meetings since they became invitees last summer. But as a full member, Finland can benefit from Article 5 mutual defense commitments — meaning allies are bound to come to its aid if it’s under attack — and the Nordic country will have to be ready to defend other allies, too.

“It’s a big change with a lot of continuity behind it,” Minna Ålander, a research fellow at the Finnish Institute of International Affairs, said of Finland’s membership to NATO. While the country has long been a close partner to the alliance, there will be a “huge change in mentality that is required because now we are not alone anymore and we can expect help,” instead of having to defend its territory on its own, Ålander said.

I congratulated President @niinisto on the completion of the historic ratification of #Finland’s accession. I look forward to raising #Finland’s flag at #NATO HQ in the coming days. Together we are stronger & safer.

— Jens Stoltenberg (@jensstoltenberg) March 31, 2023

This means Finland’s membership will double the length of NATO’s frontier with Russia, which now comprises just 6% of Russia’s land perimeter. It willl enable the alliance to improve its surveillance of Russia’s western flank with the help of Finland’s well-trained military, which already uses weapons compatible with the alliance. And while Russia poses a limited threat while it is currently bogged down in its war in Ukraine, allies don’t want to underestimate Moscow’s ability to reconstitute its forces after the war.

Finland’s membership becomes official once it deposits its accession bid with the US State Department in Washington, which could happen in the coming days.

The Finnish entry is set to enable the bloc to further secure the area around the Baltic Sea in defense of its Baltic members of Estonia, Latvia and Lithuania, which are often seen as potential targets of Russian aggression. It also brings another Arctic nation into the fold of the alliance, one whose military is trained for cold weather — an important asset at a time when the High North is gaining in strategic importance in light of increased presence by Russia and China there.

For NATO, Finland’s ratification marks one of the swiftest accessions in history, sealing membership in less than a year since the two Nordic countries applied last May. North Macedonia was last to join the alliance, a process that took two decades. Along with Sweden, other countries, including Ukraine and Georgia, are also left waiting at NATO’s door.

“Finland stands with Sweden now and in the future and supports its application,” Finnish Prime Minister Sanna Marin wrote on Twitter.

Finland’s application has now been ratified by all members and we will join NATO. Thank you to all countries for your support. As allies, we will give and receive security. We will defend each other. Finland stands with Sweden now and in the future and supports its application.

— Sanna Marin (@MarinSanna) March 30, 2023

The focus now shifts to finalizing Sweden’s bid, which allies still hope will conclude in time for a leaders’ summit in Vilnius in July. But the Turkish elections in May are seen as crucial, given that any uncertain outcome in Ankara could further delay the enlargement process. Sweden’s new anti-terrorism laws, which it hopes will go some way to sway Turkey, are scheduled to go into force in June.

The Hungarian parliament has yet to schedule a vote on Sweden’s bid, while government spokesman Zoltan Kovacs wrote in a tweet on Wednesday that “Sweden’s admission to NATO faces challenges as we’re raising concerns over lingering grievances, including diplomatic bashing and a lack of care and respect.”

“Today we are happy for Finland,” Swedish Foreign Affairs Minister Tobias Billstrom wrote on Twitter. “This is an important step forward for our sister nation and them becoming NATO members will contribute to both Sweden and Finland’s security.”

By Kati Pohjanpalo, Natalia Drozdiak and Firat Kozok
With assistance from Niclas Rolander, Beril Akman, Maria Tadeo, Tom Mackenzie, Max Ramsay and Leo Laikola.

© 2023 Bloomberg L.P.