Since the end of the Second World War, Finland and Sweden, have maintained strict policies of neutrality between Russia and NATO, viewing membership of The North Atlantic Treaty Organization as a provocation to Moscow.

Both Sweden and Finland also took a neutral stance throughout the Cold War.

With Finland already set to hand in its application, Sweden’s prime minister Magdalena Andersson is now all but certain to launch a formal application within days.

The developments come despite opposition from Turkey, warnings of retaliation from Russia, and domestic protests against the move in Sweden. 

The announcements abandon decades of military non-alignment by the two countries whose governments will now present their proposals to their respective parliaments and are expected to formally submit a joint membership application to the 30-member alliance as soon as the decisions are ratified.

Finnish President Sauli Niinisto hailed the decision as a “historic day” for the Nordic country (which shares an 810-mile - 1,300km - border with Russia) saying “the government’s foreign policy committee have agreed that after consulting parliament, Finland will apply for Nato membership,”

Niinisto spoke to his Russian counterpart, Putin, on the phone and informed him that his country aimed to join Nato, in a conversation he described as “direct and straightforward”.

According to a readout of the call released by the Kremlin Putin reportedly responded to Niinisto’s call by saying Nato membership “would be a mistake, since there is no threat to Finland’s security”. 

Likewise, Russia’s deputy foreign minister Sergei Ryabkov has said that “this is another grave mistake with far-reaching consequences, the general level of military tensions will increase.”

Ryabkov warned the two countries “should have no illusions that Russia will simply put up with their decision. It is a pity that common sense is being sacrificed for some phantom ideas about what should be done in the current situation.”

The Kremlin had also previously warned Helsinki and Stockholm against joining the bloc and promised an appropriate response should they make such a move. In the wake of the announcements, the Kremlin has said the decisions represented a hostile move that threatened Russia, warning vaguely of "retaliatory steps, both of a military-technical and other nature".

Turkey has expressed dissatisfaction over any Finnish and Swedish membership, which requires the unanimous approval of the alliance’s members. The Turkish foreign minister says that “Sweden and Finland must stop supporting terrorist groups in their countries and provide clear security guarantees.”

Speaking after a Nato foreign ministers’ meeting in Berlin, the Turkish minister Mevlut Cavusoglu said that Turkey was “not threatening anybody” but that while Finland’s approach was conciliatory, Sweden was not being so constructive.

Ankara is said to be particularly concerned about Sweden’s support for the PKK Kurdish militant group, designated as a terrorist group by Turkey.

Sweden’s ruling Social Democrats party say they back the country joining the Western military alliance NATO, abandoning decades of opposition to the move. 

In a statement, the Social Democrats said the party board held a meeting on May 15, 2022, and “decided that the party will work toward Sweden applying for membership in NATO,”

Swedish Prime minister, Magdalena Andersson, told a news conference “we believe Sweden needs the formal security guarantees that come with membership in Nato.”

She admitted her country’s non-alignment policy had served Sweden well but claims it “will not do so in the future”. 

However, the move has divided her own party, with some members arguing that the decision has been rushed through. 

The increasing sense 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.

The vice-chairman of parliament’s defense committee, Niklas Karlsson who is also a Social Democrat MP for the southern Scania region says there was a “strong majority” among his local party members to maintain non-alignment, despite concerns and hesitation caused by Russia’s offensive.

“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... If the decision is to extend the time for the discussion, I will be happy.”

Meanwhile, the Social Democrat chairman in the southern city of Helsingborg, Mikael Andersson, also criticized the Swedish process saying it has been “far too fast for such a complex issue. I am critical of the fact that it has been forced forward,” he told Swedish media. 

Anders Lindberg, the political editorialist at Aftonbladet, an independent social-democratic daily argues "It's not Sweden deciding the timeline, it's Finland because they share a 1,300-km border with Russia"

Experts say there has never been any Russian threat to Finland or Sweden. Moscow has repeatedly warned both countries against joining NATO, saying such a move would oblige it to “restore military balance” by strengthening its defenses in the Baltic Sea region, including the deployment of nuclear weapons.

An organization called "SAY NO TO NATO" has staged a demonstration against Sweden's potential membership of North Atlantic Treaty Organization in the capital Stockholm. 

Protesters argued the Swedish government's main task should be protecting the country's independence and peace and that joining NATO would run counter to that task and escalate the current situation. 

Crowds of protesters laid slogans on ground reading "North Atlantic Terrorism Organization" 

Ulf Sparrbage, an organizer of the demonstration says "we don't think that NATO is an organization for peace. NATO has been making wars without any native countries have been attacked militarily. Still, they have destroyed a large part of West Asia, Afghanistan, and so forth.”

He added that “NATO go out their own jurisdiction to fight other countries, and it has caused a lot of problems in the world. We don't want be an enemy with Russia. We believe in dialogue and try to make an agreement and so forth. We want to stay neutral with no alliance." 

Marcus McBay another protester in attendance says "I think it's a good opportunity to show that there is a lot of people, especially youth, that are against this because we are the generation that’s going to be most affected by this." 

Nato’s secretary-general, Jens Stoltenberg, has regularly said both countries would be “welcomed with open arms” and that the accession process would be quick.

Once vetted by NATO allies, approval of membership for both countries could come in just a matter of weeks. U.S. Secretary of State Antony Blinken says Washington "would strongly support the NATO application by either Sweden or Finland should they choose to formally apply to the alliance,” adding he heard "almost across-the-board very strong support" for the NATO bids. "I'm very confident that we will reach a consensus," he said.

The irony is that Ukraine has not been  “welcomed with open arms” by NATO and it’s accession process has been condemned by Kyiv for being far too slow. 

With Russia’s conflict in Ukraine sending economic and diplomatic shockwaves across the globe, experts have argued further expanding NATO toward Russian borders will not help ease the tensions.