Finland joined the NATO military alliance Tuesday, dealing a major blow to Russia with a historic realignment 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 World War II. But its leaders signaled they wanted to join the alliance just months after Russian President Vladimir Putin’s invasion of Ukraine sent a shiver of fear through Moscow’s neighbors.
The move is a strategic and political blow to 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 what will be its 31st member country.
Neighboring 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 U.S. Secretary of State Antony Blinken. The U.S. State Department is the repository of NATO texts concerning membership.
Kremlin spokesman Dmitry Peskov said 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,” Peskov said in a conference call with reporters.
But Peskov also sought to play down the impact, noting that Russia has no territorial disputes with Finland.
It’s 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.
Stoltenberg said that once it joins, Finland will benefit from NATO’s “iron-clad security guarantee,” under which all member countries vow to come to the defense 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,” Stoltenberg said.
Finland’s entry, to be marked with a flag-raising ceremony at NATO headquarters, falls on the organization’s very own birthday, the 74th anniversary of the signing of its founding Washington Treaty on April 4, 1949. It also coincides with a meeting of the alliance’s foreign ministers.
Finland’s president, foreign and defense ministers will take part in the ceremony.
Turkey became the last NATO member country to ratify Finland’s membership protocol on Thursday.