French President Emmanuel Macron has said he is considering opening France’s “nuclear umbrella” to the rest of Europe – amid uncertainties over US security guarantees.
Ahead of EU leaders meeting in Brussels on Thursday, Mr Macron said he would “open the debate” around sharing France’s nuclear deterrent with other European and NATO allies.
It comes after President Donald Trump withdrew military aid from Ukraine – and amid fears he could withdraw US involvement in NATO.
This has seen leaders in Germany, Canada, and elsewhere suggest that both France and the UK could help bolster their security as the sole nuclear powers in Europe.
Please use Chrome browser for a more accessible video player
What is a nuclear ‘umbrella’ and how does the UK’s differ from France’s?
There are only five recognised nuclear powers under the Nuclear Proliferation Treaty (NPT), an international agreement established during the Cold War to avoid nuclear destruction.
They are the UK, US, France, China, and Russia.
Other countries, including North Korea, India, and Pakistan, are believed to have nuclear weapons too – but they are not part of the NPT.
The US and Russian nuclear capabilities are by far the biggest, with America having around 1,700 nuclear warheads, compared with the UK’s estimated 250 and France’s 300.
The UK’s Trident programme is a single deterrent system – the only one in the NPT – which operates on a strategy of ‘continued at-sea deterrence’ (CASD).
This consists of four nuclear submarines, each capable of carrying missiles armed with nuclear warheads. There is always at least one patrolling UK waters at any one time – ready to respond to any foreign nuclear attack – acting as a deterrent.
Read more from Sky News
What is Starmer’s ‘coalition of the willing?’
US is ‘destroying international rules-based order’
Trump tells Hamas it’s ‘dead’ if hostages aren’t returned
The UK Trident programme is “assigned” to NATO.
As military analyst Sean Bell says, this means: “In principle, although only three members of NATO are nuclear powers (the US, France, and the UK), should any NATO country suffer a nuclear attack they would still benefit from the ‘umbrella’ of protection from the collective nuclear capability of NATO.”
France, however, has not assigned its nuclear arsenal to NATO and remains independent.
Unlike the UK – as well as submarines, it also has airborne nuclear capabilities.
Both Prime Minister Sir Keir Starmer and President Macron are the only people who have the power to ‘pull the trigger’ on their respective countries using their nuclear weapons.
What has been said?
Since Donald Trump re-entered the White House, world leaders have expressed strategic security concerns.
Mr Trump has long voiced his dislike of NATO, describing it as “obsolete”, and saying he would “encourage” Russian President Vladimir Putin to attack any NATO country that fails to pay its contributions to the alliance.
He has also suspended military aid to Ukraine, leaving many fearing that without US support, Mr Putin may be emboldened to take complete control of the country – and other former Soviet nations nearby.
Ahead of Germany’s elections, expectant chancellor Friedrich Merz said he wanted to “discuss with the British and the French whether their nuclear protection could be extended” – and “apply to us”.
This week, Chrystia Freeland, Canada’s former deputy prime minister who is running to replace Justin Trudeau as prime minister, indicated she would try to get assurances from the UK and France after Donald Trump’s suggestion Canada could become America’s ’51st state’.
She said that Mr Trump is “clearly threatening our sovereignty” and that to “guarantee our security” she would build closer partnerships with Western allies.
“I would be sure that France and Britain were there, who possess nuclear weapons,” she added.
Ahead of the latest EU summit in Brussels, Mr Macron reiterated earlier comments that he would discuss extending France’s nuclear commitments amid the uncertainties around America’s.
“I want to believe that the US will stand by our side, but we have to be ready for that not to be the case,” he said.
Sir Keir Starmer has not been drawn on the debate.
Could the umbrella be extended?
In principle, the UK’s nuclear umbrella already extends to the other 31 NATO countries – and so does America’s.
However, since Mr Trump’s re-election, the US is being seen as a “potentially unreliable partner”, former RAF pilot Sean Bell says.
This puts more pressure on both the UK and France, as Europe’s sole nuclear powers, to act as deterrents to further Russian aggression, which many fear could see countries like Latvia, Lithuania, Estonia, or Moldova invaded.
“Nuclear weapons are abhorrent by their very nature – but they are the ultimate deterrence and should never actually need to be used,” Bell says.
“Any potential adversary has to believe that the cost of any offensive attack would far outweigh any benefits.
“It is increasingly unclear whether the US policy regarding NATO and European defence has changed, raising concerns over the credibility of NATO’s nuclear deterrent capability as a result, Europe recognises that it needs a Plan B.”
The easiest way to bolster this would be for France to share its nuclear arsenal with NATO in the same way Britain does.
“If you’ve got two countries [assigned to NATO], you’ve got double the commitment – and therefore more resilience and more credibility,” Bell says.
Please use Chrome browser for a more accessible video player
Mr Macron said he would discuss the French umbrella with European leaders in Brussels on Thursday.
But Bell says: “It looks unlikely that France will announce a significant change to its long-held nuclear policy at today’s meeting.
“But it does highlight just how seriously European nations are taking this change in security approach by the Trump administration.”