The stakes couldn’t be higher and the risks couldn’t be greater when the prime minister visits Washington this weekFor British prime ministers, with their ideas about the world shaped by the histories of Churchill and Roosevelt, Maggie and Ronnie, and the rest of the folklore about the transatlantic alliance, the prospect of a visit to the White House usually causes tingles of excitement. One of our senior diplomats once offered me an explanation of the allure: “The red carpet is laid out, the national anthems are played, all that stuff is very seductive.” This will be customarily accompanied by ritualistic words about the importance and invincibility of the “special relationship”.Number 10 lobbied hard to get Sir Keir Starmer across the Atlantic early in the second term of Donald Trump and, until recently, Downing Street people were telling themselves that an encounter between the two men needn’t be a disaster and might even turn out to be a success. In the weeks since Trump’s re-e...