Finland has joined the Nato military alliance, dealing a major blow to Russia with a historic realignment of the continent triggered by Moscow’s invasion of Ukraine.
With the handing over of documents, the Nordic nation officially entered the world’s biggest security alliance, doubling its border with Russia.
Finland’s membership represents a major change in Europe’s security landscape. The country adopted neutrality after its defeat by the Soviets in the Second World War but its leaders signalled they wanted to join the alliance just months after Russian president Vladimir Putin’s invasion of Ukraine sent fear through Moscow’s neighbours.
The move is a strategic and political blow to Mr Putin, who has long complained about Nato’s expansion toward Russia and partly used that as a justification for the invasion. The alliance says it poses no threat to Moscow.
Russia warned that it would be forced to take “retaliatory measures” to address what it called security threats created by Finland’s membership.
It has also warned it will bolster forces near Finland if Nato sends any additional troops or equipment to its 31st member country.
Neighbouring Sweden, which has avoided military alliances for more than 200 years, has also applied but objections from Nato members Turkey and Hungary have delayed the process.
Finland’s membership became official when its foreign minister handed over documents completing its accession process to US secretary of state Antony Blinken. The US State Department is the repository of Nato texts concerning membership.
Mr Blinken said: “I’m tempted to say this is maybe the one thing that we can thank Mr Putin for because he once again here precipitated something he claims to want to prevent by Russia’s aggression, causing many countries to believe that they have to do more to look out for their own defence and to make sure that they can deter possible Russian aggression going forward.”
“It’s a great day for Finland and an important day for Nato too,” said Finnish president Sauli Niinisto. “Russia tried to create a sphere around them and, well, we are not a sphere. I’m sure that Finns themselves feel more secure, that we are living in a more stable world.”
Earlier, Nato secretary-general Jens Stoltenberg told reporters at the alliance’s headquarters in Brussels that “there will be no Nato troops in Finland without the consent of Finland”.
But he refused to rule out the possibility of holding more military exercises there and said that Nato would not allow Russia’s demands to dictate the organisation’s decisions.
“We are constantly assessing our posture, our presence. We have more exercises, we have more presence, also in the Nordic area,” he said.
Kremlin spokesman Dmitry Peskov said on Tuesday that Finland’s membership reflects the alliance’s anti-Russian course and warned that Moscow will respond depending on what weapons Nato allies place there.
“We will closely monitor what will be going on in Finland and how Nato will use the territory of Finland for the deployment of weapons, equipment and infrastructure next to our border that would potentially threaten us. Measures will be taken dependent on that,” Mr Peskov said in a conference call with reporters.
But Mr Peskov also sought to play down the impact, noting that Russia has no territorial disputes with Finland.
It is not clear what additional military resources Russia could send to the Finnish border. Moscow has deployed the bulk of its most capable military units to Ukraine.
Mr Stoltenberg said that Finland will benefit from Nato’s “iron-clad security guarantee” under which all member countries vow to come to the defence of any ally that comes under attack.
“By (Finland) become a full-fledged member, we are removing the room for miscalculation in Moscow about Nato’s readiness to protect Finland, and that makes Finland safer and stronger, and all of us safer,” Mr Stoltenberg said.