King skillfully appeals to Republicans fond of Britain and Democrats anxious about rules-based order in state visit

For his last trick, the king revealed a bell that hung from the conning tower of a Royal Navy submarine launched from a UK shipyard in 1944. Its name was HMS Trump. “And should you ever need to get hold of us,” Charles III said, “well, just give us a ring.”

The polished brass bell bearing the name “Trump”, presented at Tuesday’s state dinner at the White House, was an ego-flattering masterstroke that will have prompted groans in foreign capitals from Paris to Canberra to Tokyo. How can they ever hope to match that?

But for all the gushing praise on both sides of the Atlantic for Charles’s elegant display of diplomacy on his visit to the US this week, the British prime minister, Keir Starmer, would do well to remember the problem with soft power is it is soft, and can quickly scatter like blossom on the wind. Donald Trump is notorious for blowing hot and cold: while the monarch bathed in the warmth of his anglophilia, citizen Starmer can still expect the cold shoulder.

This was a trip laced with ironies. Back at home, Charles is the ailing head of a tainted family that symbolises class privilege and colonialism and would never be invented today. Yet in the US, the country that unceremoniously kicked out his great-great-great-great-great grandfather 250 years ago, he was hailed as a debonair defender of democracy.