Sanna Marin Sauli Niinistö
© Markku Ulander/Lehtikuva/AFP via Getty Images
Finland’s prime minister Sanna Marin and president Sauli Niinistö: ‘As a member of Nato, Finland would strengthen the entire defence alliance.’
Sweden moves one step closer to Nato membership on Friday with a new security policy analysis that could end a two-century tradition of neutrality and military non-alignment.

That prospect has divided Sweden's ruling Social Democrats ahead of a crunch party board meeting on Sunday - and sparked growing protest from some regional MPs at being "forced" to give rapid backing for Nato membership.

Adding further momentum to the Swedish debate on Thursday was a joint call by Finland's president and prime minister for their country's political parties to expedite their decision on alliance membership.

"As a member of Nato, Finland would strengthen the entire defence alliance," said president Sauli Niinistö and prime minister Sanna Marin in a statement.

Finland shares a long history, and a 1,300km border, with Russia, but Moscow's war on Ukraine has seen Finnish support for Nato membership rise from 28 per cent in January to 73 per cent now.

Responding to the statement of Finnish leaders, Russia said its membership of Nato would damage bilateral ties and prompt "retaliatory steps, both of a military-technical and other nature . . . to neutralise the threats to its national security that arise from this".

Russian state television said the main beneficiary of the Nato enlargement was the US, accusing president Joe Biden on Thursday of trying to erect a "new iron curtain from the Barents to the Black Sea".

Mr Niinistö hit back at Russian warnings, saying: "Joining Nato would not be against anyone. You caused this. Look in the mirror."

Earlier this week, Helsinki's parliamentary defence committee called Nato membership "the best solution for Finland's security" while, on Wednesday, Finland and Sweden signed mutual security pacts with the UK.

Parliamentary session

In Helsinki, a special committee will announce Finland's formal decision on Sunday. On Monday in Stockholm a special parliamentary session has been called after which prime minister Magdalena Andersson will reportedly make the formal decision at a special cabinet meeting. Stockholm and Helsinki have indicated they will file formal Nato membership applications in tandem.

On Thursday Sweden's minister for foreign affairs Ann Linde conceded that Thursday's Finnish declaration would "of course affect" the domestic debate.

"But Sweden has its own process and we are not yet done with it," she said, in a nod to Friday's security policy presentation.

A growing feeling of inevitability over the Nato application process has caused fury among some in the Social Democrats. Last year's party congress backed retaining Sweden's traditional policy of non-alignment while, in December, the Social Democrat-led government refused to back an opposition demand for a "Nato option" in its security policy.

At Social Democrat party meetings across the country, many MPs have reported huge resistance to Nato membership, the pace of the decision-making - and often both.

Niklas Karlsson, vice-chairman of parliament's defence committee and a Social Democrat MP for the southern Scania region, said there was a "strong majority" among his local party members to maintain non-alignment, despite concerns and hesitation caused by Russia's invasion.

"There is criticism that this is far too short a time to discuss such a complex issue," he said. "I will address this at the party board on Sunday. If the decision is to extend the time for the discussion, I will be happy."

'Far too fast'

Mikael Andersson, Social Democrat chairman in the southern city of Helsingborg, agrees that the process has been "far too fast for such a complex issue".

"I am critical of the fact that it has been forced forward," he told the Svenska Dagbladet daily.

Leading figures in the opposition Moderates say Sweden's application is a done deal.

For the liberal-conservative Moderates, long-time backers of joining Nato, Finland's move on Thursday "makes it even more obvious that Sweden should go the same way".

Moderates foreign policy spokesman Hans Wallmark, who helped draft Friday's security document, says it makes no explicit recommendation to join Nato but "when we present it, I think that will be quite clear and obvious".

"We've had two parallel but separate processes in Sweden, one for the Social Democrats and one for parliament," he told The Irish Times. "We are not there yet but all we are doing now is more or less waiting for the Social Democrats."