Defence minister Antti Häkkänen Finland and Europe’s security environment had “fundamentally and significantly changed” since Russia’s full-scale invasion of Ukraine began in 2022.

The Nordic nation abandoned decades of military neutrality to join Nato in 2023 over mounting concerns about the threat posed by Russia.

Under Finland’s 1987 Nuclear Energy Act, the import, manufacture, possession and detonation of nuclear explosives is prohibited on Finnish soil – even during wartime.

The government proposal would change that, making it possible to “bring a nuclear weapon into Finland, or to transport, deliver or possess one in Finland, if it is connected to the military defence of Finland”, Häkkänen said.

“The amendment is necessary to enable Finland’s military defense as part of the alliance and to take full advantage of Nato’s deterrence and collective defence,” he told a news conference on Thursday.

Nato’s founding principle of collective defence – that an attack on one member nation would be treated as an attack on all – underpins the alliance’s nuclear deterrence stategy.

As it contains several nuclear powers, this means a direct attack on a member brings with it the risk of a nuclear response. US nuclear weapons are stationed in several European nations, according to the Center for Arms Control and Non-proliferation.

The Finnish government’s proposal requires changes to both the country’s Nuclear Energy Act and the criminal code.

Its governing right-wing coalition, which holds a majority in parliament, said the proposal had been circulated for consultation until 2 April before it is formally laid out.

Finland shares a 1,340km (832-mile) border with Russia – the longest of any EU or Nato member state – and its leaders have repeatedly warned that the country’s security environment had deteriorated since Russia’s invasion of Ukraine.

The Nordic nation became the 31st member of Nato in April 2023, widely seen as a strategic setback for Russian President Vladimir Putin, who had long criticised the military alliance’s eastward expansion. Its neighbour Sweden joined Nato in 2024.

Since then, Nato has increased its military presence in the Arctic and Baltic Sea, as well as along the newly expanded eastern flank.

The proposal comes as European countries step up defence co-operation in response to the war in Ukraine and broader global instability.

Several Nato states suffered air traffic disruption after drones were sighted over airports and airbases last year, which some European officials attributed to “hybrid warfare” on the part of Russia.

Moscow denied involvement, but the incidents prompted renewed discussions about collective defence.

On Monday, France and Germany announced plans to deepen co-operation with European partners on nuclear deterrence.

Swedish Prime Minister Ulf Kristersson said last week that the country’s doctrine of not stationing foreign troops or nuclear weapons on its territory “would not apply” if Sweden found itself “in a completely different situation”.

As president of France in the 1960s, it was he who launched the policy of French strategic independence.

Of course, he said, Americans were more our friends than Russians are. But the US too had interests. And one day their interests would clash with ours.

In the world of today, his warnings have never seemed more clairvoyant.

From his principle of superpower detachment, De Gaulle conjured the notion of France’s sovereign nuclear deterrent – whose existence is now at the centre of debates over European security.

France and the UK are the only two countries on the European continent who have nuclear weapons. Currently France has just short of 300 nuclear warheads, which can be fired from France-based aircraft or from submarines.

The UK has about 250. The big difference is that the French arsenal is sovereign – i.e. developed entirely by France – whereas the UK relies on US technical input.

On Wednesday President Emmanuel Macron aired the idea that France’s deterrence force (force de frappe) could – in this highly uncertain new era – be associated with the defence of other European countries.

His suggestion drew outrage from politicians of the hard right and left, who say that France is considering “sharing” its nuclear arsenal.

That – according to government officials as well as defence experts – is a falsification of the argument. Nothing is to be “shared”.

According to Defence Minister Sébastien Lecornu, the nuclear deterrent “is French and will remain French – from its conception to its production to its operation, under a decision of the president.”

What is under discussion is not more fingers on the nuclear button. It is whether France’s nuclear protection can be explicitly extended to include other European countries.

Until now French nuclear doctrine has been built around the threat of a massive nuclear response if the president thought the “vital interests” of France were at stake.

The limits of these “vital interests” have always been left deliberately vague – ambiguity and credibility being the two watchwords of nuclear deterrence.

In fact French presidents going back to De Gaulle himself have all hinted that some European countries might de facto already be under the umbrella. In 1964 De Gaulle that France would consider itself threatened if, for example, the USSR attacked Germany.

So in one way there is nothing new in Macron suggesting a European dimension to France’s deterrent.

What is new, according to defence analysts, is that for the first time other European countries are also asking for it.

“In the past when France has made overtures [about extending nuclear protection], other countries were reluctant to respond,” says Pierre Haroche of the Catholic University of Lille.

“They didn’t want to send out the signal that they did not have complete faith in the US and Nato.”

“But Trump has clarified the debate,” Mr Laroche says. “It’s not that the Americans are talking of removing their nuclear deterrent – let’s be clear, that does not seem to be on the table right now.”

“But the credibility of US nuclear dissuasion is not what it was. That has opened the debate, and led the Germans to look more favourably on the idea of coming under a French and/or British umbrella.”

Last month the likely next German chancellor Friedrich Merz surprised the country’s partners by saying it might be the moment for discussion with Paris and London on the subject.

How a French or Franco-British European nuclear deterrent might operate is still far from clear.

According to Mr Haroche, one option might be to position French nuclear-armed planes in other countries, such as Germany or Poland. The decision to press the trigger would still rest entirely with the French president, but their presence would send a strong signal.

Alternatively, French bombers could patrol European borders, in the same way they regularly do French borders today. Or airfields could be developed in other countries to which French bombers could quickly deploy in an emergency.

Numbers are an issue. Are 300 French warheads enough against Russia’s thousands? Maybe not – but in an alliance with the UK 300 become 550. Also (to repeat the point) the American nuclear deterrent is still in theory in place. There are US nuclear bombs in Germany, Italy and the Netherlands.

Another question is whether to reformulate the French nuclear doctrine so as to state unambiguously that “vital interests” cover European allies too.

Some say there is no need, because the strategic vagueness that exists already is part of the very deterrent.

But Mr Haroche says there is a political dimension to stating more clearly that France will use its arsenal to defend other European countries.

“If the US is to be less present, then European countries will be depending much more on each other. Our strategic world becomes more horizontal,” he says.

“In this new world it is important to build trust and confidence among ourselves. For France to signal it is prepared to take on risk in support of others – that helps create a solid front.”

Rafael Grossi, director general of the International Atomic Energy Agency (IAEA), said Iran was increasing its stockpile of uranium enriched to 60%, just below the level of purity needed for a nuclear weapon.

This will be seen by many in the region as Tehran’s response to its military and diplomatic setbacks in Syria, Lebanon and Gaza in recent months.

Mr Grossi said it was “no secret” some politicians in Iran were calling for the development of a nuclear weapon – but after holding talks in Tehran in recent weeks, he said that “doesn’t seem to be the path of choice” by the current leadership.

Mr Grossi was speaking on the margins of the Manama Dialogue conference in Bahrain run by the London-based think tank, the International Institute for Strategic Studies.

He warned Israel against attacking Iranian nuclear facilities, saying the consequences would be “very, very serious indeed” in terms of Tehran’s retaliation and the potential spread of radiation.

He also said it was “extremely concerning” that more countries were thinking of acquiring nuclear weapons and that the public conversation about their use had become “normalised”

In a report to IAEA governors on Friday, Mr Grossi said his inspectors had confirmed Iran was feeding more partially enriched uranium into the cascades of two centrifuges at its Fordow nuclear plant south of Tehran.

“The facility’s updated design information showed that the effect of this change would be to significantly increase the rate of production of UF6 (uranium) enriched up to 60%,” the report said. It assessed the facility would produce 34kg (75lb) of 60% uranium per month compared previously with 4.7kg.

The IAEA had demanded further “safeguard measures” at Fordow “as a matter of urgency to enable the agency to provide timely and technically credible assurances that the facility is not being misused to produce uranium of an enrichment level higher than that declared by Iran, and that there is no diversion of declared nuclear material”.

Iran denies having a military nuclear programme. But Mr Grossi said that its nuclear energy facilities had increased over the last decade.

“They have a nuclear programme that has grown, has spawned in every possible direction.”The Iran of 2015 has nothing to do with Iran of 2025. Iran is starting production of 60% [uranium] at a much higher level of production, which means they will have the amounts necessary – if they so choose – to have a nuclear device in a much faster way.

So we see an escalation in this regard, which is very worrisome.”On a visit to Tehran last month, Mr Grossi said he had been given an assurance by Iranian leaders that they would limit their production of 60% enriched uranium.

Iran’s decision to increase production comes after little progress was made in nuclear talks between European and Iranian officials last week.

Mr Grossi said there were groups in Iran that were “very vocal” calling for the country to “do its own thing” on nuclear weapons.

“In my conversations with the government, that doesn’t seem to be the path of choice, but they sometimes refer to this as something they might need to reconsider. I hope not. I have told them this would be a regrettable choice.”

Israel has not yet launched a full-scale attack on Iran’s nuclear facilities – but its ministers have openly discussed the possibility.

Asked about the consequences of any such Israeli attack, Mr Grossi said: “I don’t think this would go without an answer, militarily speaking, so I think we need to avoid this.

“One should not forget that a big part of the nuclear programme in Iran is underground and very well protected. So kinetic action against the programme would require a vast deployment of force.

“I just hope that we are not going to get there. I know the radiological consequences if you attack a nuclear facility.”

Mr Grossi also warned that the world’s nuclear non-proliferation regime was under stress, as established nuclear powers “seem to be relying more on nuclear weapons or modernising their arsenals”.

As a result, other nations were talking more about acquiring nuclear weapons.

“There are countries saying: well, why not us? If we see that we have a world… with new conflicts, the big [countries] are saying that perhaps they might use the nuclear weapons they have, maybe we should think about our own security.”

Missiles, launchers and transporters stand as monuments to an era when Ukraine played a key role in the Soviet Union’s nuclear weapons programme – its ultimate line of defence.

Under the partially raised concrete and steel lid of a silo, a vast intercontinental ballistic missile (ICBM) peeks out.

But the missile is a replica, cracked and mouldy. For almost 30 years, the silo has been full of rubble.The whole sprawling base, near the central Ukrainian city of Pervomais’k, has long since turned into a museum.

As a newly independent Ukraine emerged from under Moscow’s shadow in the early 1990s, Kyiv turned its back on nuclear weapons.

But nearly three years after Russia’s full-scale invasion, and with no clear agreement among allies on how to guarantee Ukraine’s security when the war ends, many now feel that was a mistake.

Thirty years ago, on 5 December 1994, at a ceremony in Budapest, Ukraine joined Belarus and Kazakhstan in giving up their nuclear arsenals in return for security guarantees from the United States, the UK, France, China and Russia.

Strictly speaking, the missiles belonged to the Soviet Union, not to its newly independent former republics.

But a third of the USSR’s nuclear stockpile was located on Ukrainian soil, and handing over the weapons was a regarded as a significant moment, worthy of international recognition.

“The pledges on security assurances that [we] have given these three nations…underscore our commitment to the independence, the sovereignty and the territorial integrity of these states,” then US President Bill Clinton said in Budapest.

As a young graduate of a military academy in Kharkiv, Oleksandr Sushchenko arrived at Pervomais’k two years later, just as the process of decommissioning was getting under way.

He watched as the missiles were taken away and the silos blown up.

Now he’s back at the base as one of the museum’s curators.

Looking back after a decade of misery inflicted by Russia, which the international community has seemed unable or unwilling to prevent, he draws an inevitable conclusion.

“Seeing what’s happening now in Ukraine, my personal view is that it was a mistake to completely destroy all the nuclear weapons,” he says.

“But it was a political issue. The top leadership made the decision and we just carried out the orders.”

At the time, it all seemed to make perfect sense. No-one thought Russia would attack Ukraine within 20 years.

“We were naive, but also we trusted,” says Serhiy Komisarenko, who was serving as Ukraine’s ambassador to London in 1994.

“When Britain and United States and then France joined,” he says, “we were thinking that’s enough, you know. And Russia as well.”

For a poor country, just emerging from decades of Soviet rule, the idea of maintaining a ruinously expensive nuclear arsenal made little sense.

“Why use money to make nuclear weapons or keep them,” Komisarenko says, “if you can use it for industry, for prosperity?”But the anniversary of the fateful 1994 agreement is now being used by Ukraine to make a point.

Appearing at the Nato foreign ministers’ meeting in Brussels this week, Ukraine’s Foreign Minister Andriy Sybiha brandished a green folder containing a copy of the Budapest Memorandum.

“This document failed to secure Ukrainian and transatlantic security,” he said. “We must avoid repeating such mistakes.”

A statement from his ministry called the Memorandum “a monument to short-sightedness in strategic security decision-making”.

The question now, for Ukraine and its allies, is to find some other way to guarantee the country’s security.

For President Volodymyr Zelensky, the answer has long been obvious.

“The best security guarantees for us are [with] Nato,” he repeated on Sunday.“For us, Nato and the EU are non-negotiable.”

Despite Zelensky’s frequently passionate insistence that only membership of the Western alliance can ensure Ukraine’s survival against its large, rapacious neighbour, it’s clear Nato members remain divided on the issue.

In the face of objections from several members, the alliance has so far only said that Ukraine’s path to eventual membership is “irreversible”, without setting a timetable.

In the meantime, all the talk among Ukraine’s allies is of “peace through strength” to ensure that Ukraine is in the strongest possible position ahead of possible peace negotiations, overseen by Donald Trump, some time next year.

“The stronger our military support to Ukraine is now, the stronger their hand will be at the negotiating table,” Nato Secretary General Mark Rutte said on Tuesday.

Unsure what Donald Trump’s approach to Ukraine will be, key providers of military assistance, including the US and Germany, are sending large new shipments of equipment to Ukraine before he takes office.

Looking further ahead, some in Ukraine are suggesting that a country serious about defending itself cannot rule out a return to nuclear weapons, particularly when its most important ally, the United States, may prove unreliable in the near future.

Last month, officials denied reports that a paper circulating in the Ministry of Defence had suggested a simple nuclear device could be developed in a matter of months.

It’s clearly not on the agenda now, but Alina Frolova, a former deputy defence minister, says the leak may not have been accidental.

“That’s obviously an option which is in discussion in Ukraine, among experts,” she says.

“In case we see that we have no support and we are losing this war and we need to protect our people… I believe it could be an option.”

It’s hard to see nuclear weapons returning any time soon to the snowy wastes outside Pervomais’k.

Just one of the base’s 30m-deep command silos remains intact, preserved much as it was when it was completed in 1979.

It’s a heavily fortified structure, built to withstand a nuclear attack, with heavy steel doors and subterranean tunnels connecting it to the rest of the base.

In a tiny, cramped control room at the bottom, accessible by an even more cramped lift, coded orders to launch intercontinental ballistic missiles would have been received, deciphered and acted upon.

Former missile technician Oleksandr Sushchenko shows how two operators would have turned the key and pressed the button (grey, not red), before playing a Hollywood-style video simulation of a massive, global nuclear exchange.

It’s faintly comic, but also deeply sobering.Getting rid of the largest ICBMs, Oleksandr says, clearly made sense. In the mid-1990s, America was no longer the enemy.

But Ukraine’s nuclear arsenal included a variety of tactical weapons, with ranges between 100 and 1,000km.

“As it turned out, the enemy was much closer,” Oleksandr says.

“We could have kept a few dozen tactical warheads. That would have guaranteed security for our country.”

The report came as Iran prepared to hold talks with Britain, France and Germany in Geneva on Friday over its nuclear programme. Both sides agreed to continue diplomatic dialogue after the talks.

By also bringing more centrifuges already in place online, the confidential report outlined what Iran meant following a censure by the IAEA’s 35-nation Board of Governors passed last week at the request of Britain, France, Germany and the United States.

Iran had previously agreed to a demand by the UN agency to cap its stock of high-enriched uranium up to only 60 percent purity, well below the weapons-grade enriched level of 90 percent needed for a bomb.

According to the IAEA, Iran also intends to install 18 extra cascades of IR-4 centrifuges at that Natanz plant, each with 166 machines, the greater capacity meaning that it can enrich uranium at a faster pace, potentially increasing the risk of nuclear proliferation.

Tehran has repeatedly denied seeking nuclear weapons.

The talks in Geneva took place two months before US President-elect Donald Trump’s return to the White House.

During his first term, Trump pursued a policy of “maximum pressure” against Tehran, which eventually resulted in Washington’s unilateral decision to withdraw from the 2015 Iran nuclear deal with world powers and impose harsh sanctions.

Iran stepped up its nuclear enrichment in response.

Majid Takht-Ravanchi, a deputy to Foreign Minister Abbas Araghchi, represented Iran at the meeting.

Kazem Gharibabadi, Iran’s deputy foreign minister for legal and international affairs who was also at the meeting, said the two sides agreed to continue diplomatic dialogue in the near future. The European countries also confirmed continuation of political dialogue using almost identical language in their statements.

“We are firmly committed to pursue the interests of our people, and our preference is the path of dialogue and engagement,” Gharibabadi wrote on the social media platform X, saying the meetings particularly focused on Iran’s nuclear programme and lifting of sanctions.

On Thursday, the Iranian delegation met with Enrique Mora, the deputy secretary-general of the European Union’s foreign affairs arm.

Mora said on X that they held a “frank exchange … on Iran’s military support to Russia that has to stop, the nuclear issue that needs a diplomatic solution, regional tensions (important to avoid further escalation from all sides) and human rights”.

Iran’s Gharibabadi said the 27-nation bloc “should abandon its self-centred and irresponsible behaviour” on a range of issues including the Ukraine war and the Iranian nuclear issue.

The EU’s “complicit behaviour towards the ongoing genocide in Gaza” leaves it without moral authority to “preach” on human rights, Gharibabadi said.I

sraeli Prime Minister Benjamin Netanyahu said on Thursday that his country would do “everything” to stop Iran from acquiring a nuclear weapon after Araghchi warned Tehran could end its ban on developing one if Western sanctions are reimposed.