BRUSSELS — Finland won final approval Thursday to join the North Atlantic Treaty Organization after decades of misalignment, a major shift in the balance of power between the West and Russia sparked by its invasion of Ukraine.
Turkey's parliament voted the final vote needed for Finland's entry into NATO, meaning the alliance's borders with Russia will be doubled. It was a diplomatic and strategic defeat for Russian President Vladimir V. Putin, who made it clear when Russia invaded Ukraine that he intended to block NATO's eastward expansion.
With Finland on its lap, NATO will be in a stronger position to deter Moscow aggression, gaining access to a robust military, as well as Finnish airspace, ports and sea lanes. The alliance will also be better able to defend the Baltic and Arctic nations, said Matti Pesu, a security expert at the Finnish Institute of International Affairs.
James G. Stavridis, a retired four-star American admiral and former NATO military commander, called the move “a huge plus for NATO.”
“Geographically, their addition to the alliance adds a large and difficult-to-defend border that complicates Putin's calculus,” he said by email.
Finland's 830-mile border with Russia could present new vulnerabilities, but Finnish experts note that Russia will have to move the bulk of its military forces from there to sustain its war in Ukraine.
And Finland is already within range of Russian troops and nuclear-armed missiles based on the Kola Peninsula and St. Petersburg. Petersburg, “so Finland membership is not going to be a game changer,” said Pesu.
Nevertheless, the Russian Embassy in Sweden on Wednesday threatened Finland and Sweden with military reprisals if they joined NATO. Swedish membership applications are blocked by Türkiye and Hungary.
“If anyone still believes that this will somehow improve Europe's security, you can rest assured that the new member of the enemy bloc will become a legitimate target for Russian retaliatory actions, including military ones,” the embassy said in a post on its Facebook page. .
By voting in the Turkish Parliament, few documents remained for Finland, including the exchange of letters and the placement of Finland's accession document, which was already complete, with the Department of State in Washington.
Finland's leaders decided to apply for NATO membership within weeks of Russia's invasion of Ukraine 13 months ago. With their new neighbors aggressive, they decided that only NATO's commitment to collective defense could provide Finland with the security guarantees it needed.
For centuries Finland and Russia have been in conflict. During the 1939-40 Winter War, Finland fended off a Soviet invasion, although Finland had to relinquish some territories and they agreed to remain formally neutral during the Cold War.
However, after the collapse of the Soviet Union, Finland joined the European Union and developed a partnership with NATO, giving up neutrality for military impartiality and close security ties with Sweden.
It worked until Putin decided to seize Ukraine, which brought back many bitter memories in Finland of the Winter War and led to a bid for NATO membership, “hand in hand” with Sweden.
Finland plans to continue pushing for swift accession for Sweden, with which it has close military and security ties, but Sweden has said it accepts Finland's decision to join on its own.
It will be some time before Finland and NATO fully integrate their defense plans. Finland still has to decide, for example, whether it needs or will accept foreign troops or nuclear weapons on its territory, Pesu said.
Finland holds national elections on Sunday, and a final decision on NATO membership could help Prime Minister Sanna Marin and his Social Democrats campaign to stay in power in a very close race. The three largest parties appear to be tied for less than 20 percent each in the latest opinion polls.
In Turkey, President Recep Tayyip Erdogan is also seeking re-election, with a vote scheduled for May 14. Despite finally agreeing to Finland's membership in NATO, he put Sweden on hold. Erdogan claims that Sweden has become a haven for Kurdish separatists and other dissidents whom he considers terrorists.
Stockholm has made efforts to appease him, including adopting a new anti-terrorism law. NATO Secretary General, Jens Stoltenberg, said that Stockholm has fulfilled the commitments it made to Turkey at the last NATO summit in Madrid.
But Mr. Erdogan did not flinch.
His tough stance on the Kurds is popular in Turkey, and he has benefited from displays of international influence and influence within NATO, and as a potential mediator between Ukraine and Russia. Erdogan announced this week that Putin could visit Turkey on April 27 for the inauguration of the country's first nuclear power reactor, being built by Russia's state nuclear energy company Rosatom — an event clearly timed to help his political campaign.
Unlike almost all European countries, Finland did not shrink its military after the collapse of the Soviet Union. So that does a lot for a country of only about 5.6 million people.
The number of active duty military personnel in Finland's defense force is only 23,000 troops, but its wartime strength was able to grow quickly to 280,000 due to an extensive conscription system.
And Finland's artillery force is the largest and most equipped in Western Europe, with around 1,500 artillery pieces, including 700 howitzers, and 700 heavy mortars and 100 rocket launcher systems, according to an analysis by the Wilson Center, a Washington-based research organization.
As the lead designer of the icebreaker, Finland will also play a key role in conducting maritime operations in the increasingly contested Arctic region, officials said.
Hungary has also blocked the Swedish app. Hungary's leader, Prime Minister Viktor Orban, has a warm relationship with Putin and, like Turkey, continues to get gas and oil from Russia.
Mr Orban has in the past said he supports Sweden's offer, but remarks on Wednesday from his spokesman, Zoltan Kovacs, objected to what he said was Sweden's “open hostile attitude” toward Hungary and Turkey. The Hungarian government understands why Sweden is trying to become part of the alliance, said Mr. Kovacs, but “there are a lot of grievances that need to be addressed before the country's recognition is ratified.”
Hungarian officials complain that Sweden is highly critical of Hungary's constitutional and legal changes and their threats to the rule of law, even though most EU member states have expressed similar concerns.
Turkey's vote paved the way for Turkey to send acceptance letters to the United States for submission to the Ministry of Foreign Affairs alongside Finnish acceptance letters from 29 other NATO countries, in accordance with Article 10 of the NATO founding agreement.
The Department of State will then notify Mr. Stoltenberg that the conditions have been met for Finland to become a member of NATO.
Eric Schmitt reporting contributions from Washington, and Ben Hubbard from Istanbul.