There was both symbolism and substance on Sunday as European leaders and NATO allies gathered in London to try to pick up the pieces after a shattering encounter in the Oval Office between the president of a superpower and a president at war.

The symbolism was of European leaders and NATO allies gathering to stand shoulder to shoulder in a show of solidarity with Ukrainian President Volodymyr Zelenskyy, after his mauling in the White House by US President Donald Trump and his vice president JD Vance.

There was also real substance on Sunday as European and NATO allies committed to spending more on defence and stepping up to defend their borders against Russian aggression, with an eye on a US partner which, whatever Sir Keir Starmer might say, Europeans are not sure they can now rely on.

Ukraine talks latest – Zelenskyy to resign?

EU Commission president Ursula von der Leyen, emerging from over two hours of talks, spoke of the EU plan – to be presented on Thursday – to increase defence spending.

“Member states need more fiscal space to do a surge in defence spending,” she told reporters, adding Europe needed to turn Ukraine “into a steel porcupine that is indigestible for potential invaders”.

NATO secretary general Mark Rutte said he had heard new announcements from European leaders to ramp up defence spending.

After decades of outsourcing its defence to the US and cashing in the post-Cold War peace dividend on health, education and welfare spending, Europe is all too aware that it has entered different times.

Sir Keir has inserted himself into the heart of this endeavour as one of the few leaders – alongside perhaps President Emmanuel Macron of France and Georgia Meloni of Italy – capable of acting as the bridge between the Trump White House and the EU.

A Whitehall source said the prime minister “feels the urgency and knows the unique role he can play”, adding that Sir Keir is “very focused”.

After the blow-up in the White House on Friday which saw the groundwork carefully laid by Sir Keir and Mr Macron to try to secure US security guarantees for Ukraine ripped up, the PM has spent the weekend trying to get it back on track with both Mr Zelenskyy and Mr Trump.

I’m told it involves getting President Zelenskyy back to the table to do the deal, and then persuading European leaders to go beyond Twitter rhetoric and step up on defence spending, preparing now for a world with no US security guarantee for Europe, not just in Ukraine.

Sir Keir told me clearly he does not view the US as an unreliable ally, and that the plan he, Mr Macron and others put together will be presented to Mr Trump and “taken forward together”.

But it is undeniable that Europe will have to step up.

The PM spoke on Sunday of a “coalition of the willing”, made up of nations prepared to defend a deal in Ukraine and to guarantee peace.

“Those willing will intensify planning now with real urgency,” he said, confirming that the UK is “prepared to back this with boots on the ground and planes in the air, together with others”.

The hope is that the commitment from European allies will be enough for the US to provide the last resort backstop if Russian President Vladimir Putin decides to break the terms of any deal. It would involve intelligence and air cover but not boots on the ground.

There is tentative optimism once more in Number 10, knocked sideways by its own diplomatic triumph on Thursday being followed by Mr Zelenskyy’s Washington setback.

“There is still a way to go, but we feel like we’re making progress,” one government source said, while another told me the PM was “pleased at the quality of the discussion at the summit and feels like things are moving forward”.

When I asked another if they were confident they could bind President Trump back in, they said they were “hopeful, not confident”.

Of course, getting talks back on track is only the first hurdle of many.

Even if Sir Keir and Mr Macron can patch things up with Mr Trump and Mr Zelenskyy, what might this peace deal look like, and crucially will Russia, perhaps emboldened by the fracturing of the Western alliance, be less minded to deal or make undeliverable demands?

The PM said on Sunday that it was up to Europeans to set the parameters of a peace deal rather than allow Russia to “dictate the terms of any security guarantees before we’ve even got to a deal”.

👉 Follow Trump 100 on your podcast app 👈

Mr Trump has offered Mr Putin one concession by ruling out Ukraine joining NATO, reversing the stance adopted by his predecessor, Joe Biden.

He also batted away President Zelenskyy’s demand that Ukraine’s borders be restored to pre-conflict lines, saying he would freeze the borders at the point of any ceasefire, meaning Moscow would keep hold of the 20% of Ukrainian territory it had taken since 2022.

Read more:
‘Coalition of the willing’ to back Ukraine
Hard power is the real currency again
Starmer’s place as Trump’s new BFF tested

Last week, Mr Trump appeared less clear on this, telling reporters in the Oval Office for Sir Keir’s visit that he would get back Ukrainian land.

In short, even if the Europeans can patch up relations between President Zelenskyy and President Trump, there is an even more complex negotiation to then have with President Putin.

So, there is still quite some distance to travel, but the prime minister closes this week of intense, and fraught diplomacy, with a sense that the UK and other key partners are back on track and, as President Zelenskyy returned to the frontline in Ukraine on Sunday evening, European leaders know they have to deploy all the hard and soft power they have to try to end this war.