Promises of security guarantees for Ukraine have been lauded as “game-changing” and “historic” in the hope of bringing an end to the war with Russia.

As all eyes moved from Donald Trump’s summit with Vladimir Putin in Alaska to talks with Volodymyr Zelenskyy in Washington, the White House claimed Russia has agreed to the US providing ‘NATO-style protection’ when the fighting ends.

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Although there has been no confirmation from the Kremlin, Ukraine, the UK, and other Western allies say details of a post-war security agreement will be finalised in the coming days.

What has been said so far?

Security guarantees have long been talked about as a way of ensuring peace in Ukraine when fighting comes to an end.

Since March, when the UK and France spearheaded a largely European ‘coalition of the willing’ and potential peacekeeping force, many have claimed it would be ineffective without American backing.

The US has repeatedly refused to be drawn on its involvement – until now.

Two days after Mr Putin travelled to Alaska for talks with the Trump team, US special envoy Steve Witkoff claimed Russia had agreed to Ukrainian security guarantees.

He claimed that during the summit, the Kremlin had conceded the US “could offer Article-5 like protection”, which he described as “game-changing”. Article 5 is one of the founding principles of NATO and states that an attack on any of its 32 member states is considered an attack on them all.

This was bolstered by the US president himself after he met his Ukrainian counterpart in Washington on Monday. He said the pair had “discussed security guarantees”, which would be “provided by the various European countries” – “with coordination with the United States of America”.

Writing on X the following day, the Ukrainian leader said the “concrete content” of the security agreement would be “formalised on paper within the next 10 days”.

US reports say security agreement talks will be headed by Secretary of State Marco Rubio.

What would security guarantees look like?

Very few details have emerged so far, despite the series of high-profile meetings.

Speaking to Fox News on Tuesday, Mr Trump said European nations are going to “frontload” the security agreement with soldiers.

“They want to have boots on the ground”, he told the broadcaster, referring to the UK, France, and Germany in particular.

He insisted the US would not send ground troops, adding: “You have my assurance and I’m president.”

Sir Keir Starmer said the coalition of the willing is “preparing for the deployment of a reassurance force” in the event of “hostilities ending”.

This was the original basis for the coalition – soldiers from various European and allied nations placed strategically across Ukraine to deter Russia from launching future attacks.

But troops alone are unlikely to be enough of a deterrent for Vladimir Putin, military analyst Sean Bell says.

“This is all about credibility and I don’t think boots on the ground is a credible answer,” he tells Sky News.

Stationing soldiers along Ukraine’s 1,000-mile border with Russia would require around 100,000 soldiers at a time, which would have to be trained, deployed, and rotated, requiring 300,000 in total.

The entire UK Army would only make up 10% of that, with France likely able to contribute a further 10%, Bell says.

Several European nations would feel unable to sacrifice any troops for an umbrella force due to their proximity to Ukraine and risk of further Russian aggression.

“You’re not even close to getting the numbers you need,” Bell adds. “And even if you could, putting all of NATO’s frontline forces in one country facing Russia would be really dangerous – and leave China, North Korea, Iran, or Russia free to do whatever they wanted.”

‘Article 5-like protection’

When Mr Witkoff first mentioned security guarantees again, he described them as “Article 5-like” or “NATO-style”.

Article 5 is one of the founding principles of NATO and states that an attack on any of its 32 member states is considered an attack on them all.

It has only ever been invoked once since its inception in 1949 – by the US in response to the 9/11 attacks of 2001.

Russia has repeatedly insisted Ukraine should not be allowed to join NATO and cited the risk of it happening among its original reasons for attacking Kyiv in 2022.

NATO general-secretary Mark Rutte has said Ukrainian membership is not on the table, but that an alternative “Article 5-type” arrangement could be viable.

The alliance’s military leaders are due to meet on Wednesday to discuss options.

It is not clear how such a special security agreement and formal NATO membership would differ.

Bell says that negotiations on this – and any surrendering of Ukrainian territory – will be the two most difficult in ending the war.

But he stresses they are both key in providing the “flesh on the bones” to what the coalition of the willing has offered so far.

“It will be about trying to find things that make the Western commitment to the security of Ukraine enduring,” Bell adds.

US airpower, intelligence and a better Ukrainian military

Other potential options for a security agreement include air support, a no-maritime zone, intelligence sharing, and military supplies.

Imposing either a no-fly over Ukraine or no-maritime zone across the Black Sea would “play to NATO’s strengths” – as US air and naval capabilities alone far outstrip Russia’s, Bell says.

Sharing American intelligence with Kyiv to warn of any future Russian aggression would also be a “massive strength” to any potential deterrence force, he adds.

Ukraine is already offering to buy an extra $90bn (£66.6bn) in US weapons with the help of European funds, Mr Zelenskyy said this week.

And any security agreement would likely extend to other military equipment, logistics, and training to help Ukraine better defend itself years down the line, Bell says.

“At first it would need credible Western support, but over time, you would hope the international community makes sure Ukraine can build its own indigenous capability.

“Because while there’s a lot of focus on Ukraine at the moment, in five years’ time, there will be different governments and different priorities – so that has to endure.”