<a href="https://www.thenationalnews.com/tags/finland/" target="_blank">Finland</a> will decide in weeks whether to join <a href="https://www.thenationalnews.com/tags/nato" target="_blank">Nato</a>, Prime Minister Sanna Marin said on Wednesday, as the Nordic country and its neighbour <a href="https://www.thenationalnews.com/tags/sweden/" target="_blank">Sweden</a> rethink their security posture after Russia’s invasion of <a href="https://www.thenationalnews.com/tags/ukraine/" target="_blank">Ukraine</a>. It came as a landmark review of Finland’s defence policy said joining Nato would help it deter an attack from its large eastern neighbour and that the window could close if Russia builds pressure against an expansion. But it also warned that joining Nato would double the alliance’s 1,200-kilometre border with Russia, bring its forces closer to St Petersburg and thereby risk provoking the Kremlin. Russia has <a href="https://www.thenationalnews.com/world/europe/2021/12/28/sweden-and-finland-dragged-into-russias-stand-off-with-nato/" target="_blank">threatened consequences for Finland and Sweden</a> if they abandon their Cold War-era neutrality in favour of joining Nato, with both countries on guard for potential meddling as they weigh up the pros and cons. The leaders of the two nations are seeking cross-party consensus before lodging any application, after Russia’s onslaught on Ukraine shifted public opinion towards Nato. “We have to wonder: what is the best way to secure that this wouldn’t ever happen in Finland?,” Ms Marin said at a press conference in Stockholm with Swedish Prime Minister Magdalena Andersson. Finland’s parliament will next week begin considering the report published on Wednesday, but “I think it will happen quite fast … within weeks, not within months”, said Ms Marin, who said there were pros and cons to Nato membership. Ms Andersson said a Swedish defence review was due by late May and that the debate should not drag on into an election campaign in the autumn. Nato will update its first strategic blueprint for the first time in 12 years at a June summit, making that meeting in Madrid a possible decision point for any application by Sweden and Finland. All 30 current members would have to approve their membership, but they already have close ties with Nato and the US says it would not expect any major resistance to them joining. Allies have increased co-operation with Sweden and Finland since Russia invaded Ukraine and invited them to several diplomatic summits. They recently took part in 30,000-troop Nato drills in Norway, known as Cold Response. Ukraine, Georgia and Bosnia and Herzegovina also have Nato aspirations, although Kyiv has signalled it would be willing to drop that in <a href="https://www.thenationalnews.com/world/europe/2022/03/31/germany-willing-to-be-one-of-ukraines-protectors-in-peace-treaty/" target="_blank">a potential peace agreement with Russia</a>. President <a href="https://www.thenationalnews.com/tags/vladimir-putin/" target="_blank">Vladimir Putin</a> has long viewed Nato’s expansion towards Russia’s borders as a threat to his country and accused western leaders of breaking promises made after the break-up of the Soviet Union. Nato rejects this narrative and says Russia only has itself to blame for motivating neighbours such as <a href="https://www.thenationalnews.com/tags/poland/" target="_blank">Poland</a> and the Baltic states to shore up their troop numbers. But the 53-page Finnish review said Russia was likely to keep pressing its demands to stop Nato expansion and that failing to react to its aggressive posture could lead to a “narrowing of Finland’s room for manoeuvre”. It said Nato membership would change a relationship with Russia which Finland has long tried to stabilise, in view of their 1,340km border and troubled history, but that it would “aim to continue functioning relations with Moscow. Ms Andersson had said as recently as December that Sweden “will not apply for membership of Nato”, while Ms Marin said in January that a Finnish application was “very unlikely” during her term, but both described the security environment as having changed since Russia's invasion. Nato’s Article 5 guarantee that allies will come to each other’s defence would provide a “considerably stronger” deterrent to any Russian aggression and thereby improve the stability of the Baltic, the Finnish report said. Ms Andersson said the security offered by Article 5 could not be replaced by other arrangements, although it would commit Sweden to defending 29 other countries if they were attacked. Any enlargement would bring the countries under the umbrella of Nato’s nuclear-weapons sharing agreement, although it would not require British, French or American nuclear weapons to be stationed in Finland. However, Finland’s accession would also “significantly expand the area of the alliance, double its land border with Russia, and move the alliance closer to strategically important areas in Russia” such as St Petersburg and the Arctic Kola Peninsula, the report said. Officials say attempts to meddle in the Finnish debate could include cyberattacks, increased tensions on the border with Russia, or other risks that are difficult to anticipate. “We do have a big next-door neighbour which acts like this,” said Ms Marin, who added that it would be preferable if Sweden and Finland made similar decisions, but did not come down on one side or another herself. “There are both short-term and long-term risks,” she said of the possibility of Finland joining Nato. “These risks are there both if we apply and if we do not apply.”