Finland must apply to join Nato “without delay” in the wake of Russia’s attack on Ukraine, its president and prime minister have said, signalling a historic shift in the country’s security policy that drew a blunt warning of retaliation from the Kremlin.
With neighbouring Sweden expected to follow suit, Sauli Niinistö, Finland’s president, and Sanna Marin, the prime minister, made the call in a joint statement, adding: “We hope that the national steps still needed to make this decision will be taken rapidly within the next few days.”
Nato membership would strengthen Finland’s security, the two leaders said, and as a member of Nato, “Finland would strengthen the entire defence alliance. Finland must apply for Nato membership as a matter of urgency”.
The Kremlin spokesperson, Dmitry Peskov, said Russia would “definitely” see Finnish membership as a threat, and the foreign ministry in Moscow said it would have to take “military-technical” steps if Helsinki applied for Nato accession. “The expansion of Nato and the approach of the alliance to our borders does not make the world and our continent more stable and secure,” Peskov said. “Everything will depend on how this process takes place, how far the military infrastructure moves towards our borders.”
Russia’s foreign ministry said Moscow would be “forced to take reciprocal steps … to address the resulting threats to its national security”. It accused Nato of seeking to create “another flank for the military threat to our country” and said Helsinki should “be aware of its responsibility and the consequences of such a move”.
The Finnish daily Iltalehti reported that key Finnish politicians had been told Russia could halt gas supplies to Finland on Friday, although it did not say where the warning came from or whether it was in response to the Nato announcement.
Finland shares an 810-mile (1,300km) border with Russia and has for decades maintained a strict policy of military non-alignment, viewing membership of the US-led alliance as an unnecessary provocation of Moscow.
However, Vladimir Putin’s invasion of Ukraine on 24 February has led to a profound change in its thinking, and looks likely to usher in the very expansion of the western military alliance that the Russian president aimed to prevent.
Public support for Nato membership has trebled in Finland, with the latest poll by the public broadcaster Yle showing 76% of Finns in favour compared with about 25% before the invasion, with only 12% against.
The president, prime minister and senior cabinet ministers will meet on Sunday to make the formal decision on submitting Finland’s membership application. A positive decision would then be presented to parliament for approval early next week.
Sweden’s ruling Social Democrats are scheduled to decide on Sunday whether to overturn their longstanding opposition to Nato membership, paving the way for a probable application from Stockholm also to join the 30-nation alliance.
Sweden’s foreign minister, Ann Linde, said Niinistö and Marin’s statement was “an important message”, adding that Finland was “Sweden’s closest security and defence partner” and its assessments “must be taken into account”.
Sweden’s Expressen daily, citing unnamed sources, said Stockholm’s final decision would be made on Monday, with a formal application for membership to be submitted soon afterwards. Nordic media have previously said the two countries were likely to submit a joint application.
Nato’s secretary general, Jens Stoltenberg, said Finland would be “warmly welcomed” into the alliance and promised the accession process would be “smooth and swift”, although ratification by all 30 members could take several months.
Finland is one of Nato’s “closest partners, a mature democracy, a member of the European Union, and an important contributor to Euro-Atlantic security”, Stoltenberg said, adding that Finnish membership would prove that the alliance’s “door is open”.
Russia has repeatedly warned Finland and Sweden against joining Nato, saying the “serious military and political consequences” of such a move would oblige it to “restore military balance” by strengthening its defences in the Baltic Sea region, including by deploying nuclear weapons.
Dmitry Medvedev, the former Russian president, said on Thursday that western countries’ “proxy war with Russia” would “increase the likelihood of a direct and open conflict between Nato and Russia”.
Urging the west not to “lie to yourself and others” and “choke in the paroxysms of Russophobia”, Medvedev said such a conflict “always has the risk of turning into a full-fledged nuclear war” and that this would be “catastrophic for everyone”.
Other governments in the region, however, welcomed Helsinki’s statement. Denmark’s prime minister, Mette Frederiksen, said Finnish membership would “strengthen Nato and our common security”. Copenhagen would do everything for a quick admission process, she said.
Germany’s chancellor, Olaf Scholz, tweeted his support, saying he had assured Niinistö of “the full support of the federal government” in a phone call. Estonia’s prime minister, Kaja Kallas, said her country supported Finland’s rapid accession.
Poland’s prime minister, Mateusz Morawiecki, said Finland’s decision was “great news for Poland and Europe’s security”, and the prime minister of the Czech Republic, Petr Fiala, said his country would “of course” support a Finnish application to join the alliance.
Finland’s foreign minister, Pekka Haavisto, told the European parliament accession to Nato would strengthen security in the region. Norway, Denmark and the three Baltic states were already Nato members and the addition of Finland would “bring added value”, he said.
Finland and Sweden are officially non-aligned but became Nato partners – taking part in exercises and exchanging intelligence – after abandoning their strict neutrality when they joined the EU in 1995 after the end of the cold war.
Finland declared independence in 1917 after more than a century of Russian rule, and its heavily outnumbered army twice fought off Soviet forces during the second world war before ceding some border territory. Sweden has not fought a war for 200 years.
Marin and her Swedish counterpart, Magdalena Andersson, said at a joint press conference last month that Russia’s invasion of Ukraine had changed Europe’s whole security landscape and “dramatically shaped mindsets” in the Nordic countries.
Nato’s common security guarantee rests on article 5, the alliance’s cornerstone, which says an attack on one Nato member is an attack on all. It has been invoked only once in the organisation’s history, in response to the 9/11 terrorist attacks.