Jets, intelligence or troops: What could a US security backstop in Ukraine look like?

Independent

27-02-2025

Sir Keir Starmer has renewed his call for the US to provide a 'backstop' security guarantee in Ukraine to deter Russia from invading again in the event of a peace deal between the two nations.
Speaking on his flight to Washington DC to meet president Donald Trump, the prime minister said 'there is no issue between' the UK and US on Ukraine, despite the two leaders having appeared at odds in recent weeks over the role European nations and the US should play in any peacekeeping operation in Ukraine.
President Trump's administration has played up the chances of a deal to end Vladimir Putin's three-year full invasion – but has downplayed the prospect of Ukraine joining Nato and said it is 'unrealistic' to expect the nation's pre-2014 borders [before Russia illegally annexed the region of Crimea] to be restored.
Speaking earlier in February, new US defence secretary Pete Hegseth said the country would not longer "tolerate an imbalanced relationship" with its European allies in Nato. He added that these members must begin providing the majority of military aid to Ukraine and take on safeguarding responsibilities.
This includes "capable European and non-European troops" to be deployed as peacekeepers Mr Hegesth said. However, he added that the troops must be deployed on a non-Nato mission, meaning the organisation's Article 5 – which guarantees collective security – would not be triggered. Essentially, this would waive the US's obligation to intervene.
Only a few days later, Sir Keir said he was ready to put British troops on the ground in Ukraine 'if necessary' to guarantee the country's security. He later added that Nato troop presence in Ukraine must be backed by a US security 'backstop.'
Speaking to reporters over the Atlantic ahead of a meeting with Mr Trump on Thursday, Sir Keir clarified: 'The reason I say the backstop is so important is that the security guarantee has to be sufficient to deter Putin from coming again.
'Because my concern is if there is a ceasefire without a backstop, it will simply give him the opportunity to wait and to come again because his ambition in relation to Ukraine is pretty obvious, I think, for all to see.
'We will play our part and I've been clear that we will need a US backstop of some sort,' he added.
The issue is likely to be a source of tension between the two leaders today as they meet for the first time since Trump's election victory in November.
What would a US backstop in Ukraine look like?
What kind of security guarantee Sir Keir wants the US to commit to is unclear.
En route to Washington DC, he said: "Exactly what the configuration of that is, exactly what the backstop is, is obviously the subject of intense discussion but I'm not going to get ahead of myself on it, other than to say I'm very clear about what the principles are."
He faces a difficult task, with President Trump ruling out any such commitment. He told reporters on Wednesday: "I'm not going to make security guarantees beyond very much.
"We're going to have Europe do that, because we're talking about Europe as the next door neighbour."
If the US were to provide a backstop to European troops on the ground in Ukraine, it's unlikely it would be in the form of troops on the ground.
Former four-star US Air Force general Philip Breedlove says it would instead be a matter of supporting with intelligence and providing air support. Speaking to BBC's Radio 4 Today programme, he said the US needs to 'correct' the idea that it is telling Europe 'if you get into a dust-up with Russia, we're not gonna be there.'
'We need to correct that publicly, clearly,' he said. 'We, the United States, may not put boots on the ground, I understand our president.
'But the United States can still provide a backstop by first supplying all of that great intelligence that we have given Ukraine in the past we need to give them into the future.
'And we have airpower that could be that backstop,' he added. 'Basically, if Mr Putin tries to run over Nato troops, the United States could be that backstop via airpower.'