US aid pause raises stakes for Starmer over Ukraine

President Trump's decision to pause military aid to Ukraine may well prove to be one of the most significant moments in the conflict since Vladimir Putin launched his full-scale invasion.

As far as the UK is concerned, it will not change Sir Keir Starmer's approach, but makes the issues he has been focusing on for the past few days more acute and more urgent.

The prime minister still views his core tasks as finding a way to bring presidents Trump and Zelensky back together, and drawing up the foundations of a workable peace deal that can be presented to the US.

As we saw in the House of Commons on Monday, where MPs from different parties lined up to laud the prime minister for his sure-footed diplomacy, it is a strategy with broad support across the political spectrum.

But how deep is that support? We may be about to find out.

It is one thing for the prime minister to vow to do all he can to bring presidents Trump and Zelensky back together.

But to be a bridge between both countries, Sir Keir will in time need evidence that he has influence on both sides of that bridge.

Towards the end of his statement in the Commons, the prime minister was asked about US media reports that Trump was considering withdrawing military aid.

He replied that this was not his understanding of the US position. Evidently, this shortly turned out to be wrong.

We now know that at some point later on Monday, Starmer and Trump spoke on the phone - their third phone call in four days.

But we do not know whether Trump gave Starmer prior warning of his decision on military aid or not.

It may be that Starmer tried to persuade Trump not to go ahead and failed. Or it may be that Trump did not tell Starmer what he was about to do.

Neither of those scenarios would be especially positive for the prime minister.

As it is, it seems Downing Street is still waiting on full details of the US administration's decision and how it will work.

And it is worth stressing that this is a temporary pause in aid, not a permanent cessation. It may simply be another attempt by Trump to pressure Zelensky. The aid may resume.

Or, this may be the clearest example that - despite the unquestionable warmth Starmer has managed to foster with the US president - the fundamental frames through which they view this conflict and the western alliance more generally are irreconcilably different.

Into this increasingly fraught transatlantic environment has come JD Vance, the US vice-president, scoffing at the idea Ukraine could be protected by "20,000 troops from some random country that hasn't fought a war in 30 or 40 years".

So far only the UK and France have publicly committed troops towards policing any potential peace deal in Ukraine, and his comments were interpreted by many as having been a jibe at both countries.

Vance has now insisted he was talking about other, unnamed countries - confining the diplomatic fallout for the time being.

Yet even if Vance was referring to other countries which might be willing to take on some of the military burden of protecting Ukraine, it is hardly encouraging for the UK in its convening role in Europe if the response of the US vice-president is to mock their capabilities.

Perhaps that is merely a more blunt-speaking approach from a new US administration determined to do away with niceties.

After all, most European countries are now admitting themselves that their defence spending has been far too low for far too long.

But all the signs suggest that before long, questions about Sir Keir Starmer's approach to Ukraine may give way to much more fundamental questions about Britain's place in a profoundly changed world.