All of that has changed, as the Nordic nation braces for a presidential vote that begins on Sunday to determine Niinisto’s successor.

Russia has become highly unpredictable and a European deterrent has yet to emerge.

The US, not the European Union, replaced Russia at the centre of Finnish foreign and defence policy last year as Finns abandoned seven decades of non-alignment to join NATO.

Relations with China are fraught with suspicion after a Chinese cargo vessel’s anchor damaged the Baltic Connector gas pipeline and data cables in the Gulf of Finland last October. It may have been the same ship that damaged undersea data cables to Taiwan earlier last year. There has been suspicion of Russian-Chinese collusion.

Finland has traditionally based its security on a careful relationship with Russia.

Finnish presidents have cultivated Russian leaders as few Westerners have done, and Niinisto had a very long personal experience of dealing with Putin.

Finland’s defence budget remained measuredly below 1.5 percent of GDP throughout the Cold War and until 2020, according to figures from the Stockholm International Peace Research Institute (SIPRI).

Finland even lent its name to this pragmatic self-containment – Finlandisation.

‘Look in the mirror’

Russia’s invasion of east Ukraine and Crimea in 2014 put the country on alert.

Niinisto told parliament this demanded an investment in defence that is “perhaps greater than we have so far discussed” to protect its 1000km (621-mile) long land border with Russia, now NATO’s longest.

The turning point was Russian President Vladimir Putin’s ultimatum to NATO in December 2021 – to expel former Warsaw Pact members from the alliance and cauterise NATO expansion into eastern Europe.

That, Niinisto told Bloomberg, “was a real game changer in Finnish thinking”.

When Russia invaded Ukraine the following February, Finnish public opinion changed overnight.

Asked by an Yle survey in the first week of the invasion if they favoured NATO membership, 53 percent of Finns said yes. If the president supported it, the majority rose to 63 percent.

Following a border crisis in which Russia attempted to send asylum seekers en masse to Finland last autumn, approval for NATO membership rose to over 80 percent.

Niinisto and Putin spoke for the last time in May 2022.

“Niinisto only called Putin to inform him Finland is joining NATO, and that was this famous call where he said, ‘Look in the mirror… this is your doing’,” Minna Alander, a research fellow at the Finnish Institute of International Affairs, told Al Jazeera.

“After that he was asked, ‘What do you think about [German chancellor Olaf] Scholz and [French President Emmanuel] Macron calling [Putin] and why are you not calling Putin? Do you think you should call?’ – he was like, ‘Well I have nothing to say.’”

Boosted defence strategies for a new era

Finland’s defence posture has changed dramatically since then.

This year defence spending is to reach 2.3 percent of GDP, surpassing NATO’s two percent recommended minimum for the first time.

This will help pay for a “smart fence” along Finland’s border equipped with sensors and drones, a new set of corvettes for the navy and new howitzers for the army.

Finland bought 64 F-35 Lightning II fighter-bombers from the US’s Lockheed Martin for $9.4bn in February 2022. These are fifth-generation stealth planes. In them, the Finns could in theory fly to Moscow undetected.

Last November Finland sparked controversy when it bought the David’s Sling medium-range (40-300km, or 20-250 miles) air defence system from Israel’s Rafael.

The system is designed to intercept antiballistic missiles, used to deliver nuclear bombs. Some strategists believe that undermines reciprocal nuclear deterrence. It was a similar move by US President George W Bush to place ballistic missile interceptors in front-line NATO states that sparked Russia’s ire in 2009.

Beyond the capabilities Finland is developing on its own, it has signed a Defense Co-operation Agreement with the US that allows US forces to operate from its soil.

In other words, Russia’s invasion of Ukraine brought the full might of the Pentagon to its doorstep.

Niinisto was already the only Finnish president to be elected with an outright majority (62.7 percent) in a first voting round, in 2018. His shepherding of Finnish sentiment into concrete policy increased his stature, because the Finnish president is commander in chief of the armed forces and constitutionally leads defence and foreign policy. Since 2021 his popularity ratings have been over 90 percent.

A citizens’ movement even tried to bend the rules to allow Niinisto to stand for a third term, a campaign he was not interested in.

Unsurprisingly, the two frontrunners, former premier Alexander Stubb and former Foreign Minister Pekka Haavisto have been trying to emulate him.

“There is a sense that voters are looking for a mini-Niinisto,” said Alander.

Nuclear weapons, future challenges and NATO politics

Niinisto will now bequeath a presidency that is increased not only in stature but also in complexity.

“Without a doubt, the Finnish presidency is becoming a stronger institution because of the president’s role in foreign policy,” SM Amadae, programme director for global politics and communication at the University of Helsinki, told Al Jazeera.

About two-thirds of Finns are against reducing the president’s powers, which are largely discretionary and shaped by the force of each president’s personality and popularity.

“The next president will play an important, precedent-setting, role in how Finland’s relationship with NATO will be conducted,” she said.

Finland’s special relationship with and understanding of Russia has been its selling point in the EU and NATO until now. Its vantage point from which to spy on Russia, its cutting-edge 5G telecommunications industry and AI industry may now replace that as strategic advantages.

For these reasons, the all-important relationship with the US is likely to flourish.

“We can expect further collaboration between the US and Finland with respect to military collaboration and business partnerships,” said Amadae.

Like the other Baltic and Nordic states, Finland plays an increasingly important role in the EU.

They have been Ukraine’s staunchest EU supporters, leading traditional heavyweights France, Germany and Italy, and forming a powerful foreign policy bloc within the EU.

The next president also has some divisive issues to adjudicate. One is whether to hand to Ukraine its ageing F-18 Hornets once its F-35s become operational, further raising Russian ire.

Another is whether to allow nuclear weapons on Finnish soil. In an opinion survey conducted by Amadae and her team at the University of Helsinki, only one in every five surveyed Finns agreed.

Yet another is whether to abolish military neutrality for Aland, an autonomous cluster of islands belonging to Finland. Doing so would provide contiguous NATO territorial waters stretching to Sweden, which is inching towards NATO membership.

About half of Finns say Aland should now be militarised. Yet Stubb and Haavisto have remained noncommittal.

There are other divisive military questions.

Should Finland, with 60,000 soldiers and 300,000 trained reservists, also allow the conscription of women? Stubb says yes, Haavisto no.

Should it withdraw from the Anti-Personnel Mine Ban Convention, allowing it to mine its vulnerable border with Russia? Stubb and Haavisto say no.

“These issues have not been taken up prominently in the Presidential election campaigns or debates,” said Amadae, possibly because of this frontier country’s aversion to discord.

On one thing Finns, who fought Russia in 1939, appear to agree: Ukraine must be supported.  “We, too, have fought for our freedom and independence against an enemy far greater in size and paid a high price for it,” Niinisto told the UN General Assembly in September.

“We do not want to see the world regress to a state where the big consider it their privilege to subjugate the small.”