The president has just four years until a successor takes the reins, but the new approach he has forged – exceptionalist, isolationist – is likely to endure

Keir Starmer, it turns out, is at his best in a crisis. He has faced two since he became prime minister last year, one domestic, the other international. The first came with the riots that followed the Southport killings, when Starmer’s response was impressive and effective. The second is Donald Trump’s attempt to stitch up Ukraine, where Starmer has been surefooted in trying to hold the line against a sellout to Russia. In both cases, he has looked like the right person in the right place at the right time.

There was another example of this deftness on Wednesday in the Commons, when Starmer went out of his way to mark the anniversaries of the deaths of UK service personnel in 2007 and 2012. A total of 642 died in the Afghanistan and Iraq wars alongside their US allies. They would not be forgotten, he said. The name of JD Vance was not mentioned. Nor was the US vice-president’s contemptuous “some random country” insult this week. But Starmer’s reprimand was unerring.