In the end, it was a royal triumph, as King Charles and Queen Camilla managed to avoid all the mines in their path (the strait of Hormuz is not the only place where they exist), and deftly repair the “special relationship”. For another few weeks, anyway.

There were plenty of reasons to be anxious, on both sides of the Atlantic, before the king’s visit to Washington and New York. It is no secret that Donald Trump’s war of choice against Iran has alienated Great Britain, and all of the Nato allies, who were not consulted in advance of the decision and have since been browbeaten for what Trump perceives as insufficient fealty.

During his many fits of pique, the president has attacked Keir Starmer with particular ferocity, simply because the prime minister briefly refused British basing rights to Americans at the outset (Starmer later reversed course). That has deepened an Anglo-American rift that was already widening over Greenland, tariffs, the Chagos Islands, and the Epstein files, which, oddly, have caused more damage in the UK than in the US (for the moment, at least).

Unsurprisingly, these tensions have degraded relations. Some in Parliament were calling on King Charles to cancel the trip. Wisely, he kept calm and carried on, charming nearly all constituencies in the United States (not a simple task, given how divided the country is).

The carefully choreographed visit included a stately speech to Congress, interrupted many times by standing ovations. The speech was better, perhaps, than a dysfunctional Congress deserved, full of wit, learning, and a deep understanding of US history.

It might have been awkward for Charles to celebrate a Declaration of Independence that called his ancestor George III a tyrant; or to honor a revolution that separated 13 large colonies from the realm.

But he did so gracefully, quoting the Declaration’s egalitarian phrases with far more assurance than Trump ever has. Daringly, he slipped in statements that might even be perceived as critiques, if not so artfully tucked into otherwise glowing paragraphs about the relationship. The king asserted his respect for the limits on the executive that fortify democracy in both countries (something that speaker Mike Johnson, seated behind the King, seems loath to articulate). And he slipped in several stirring environmental thoughts, including a paean to “nature” (an important word in the Declaration), and a strong adverb – “disastrously” – to describe the melting icecaps in the Arctic. Though not quite a Love Actually moment, in which a British leader dresses down a rude president, still, it was impressive, like watching a skilled fencer overcome a slow opponent with a rapier.

The state dinner continued the love-fest, with more charming remarks, and Trump on his best behavior, beaming toward the king throughout the evening. Even a notoriously hard-to-please audience, America’s late night comedians, were besotted.

Charles scored another hit with his gift – a brass bell from the HMS Trump, a British submarine that served in the second world war. It was not quite a royal orb, but close, and the president was obviously bedazzled. So bedazzled that he tried to enlist the support of the King by asserting (without evidence) that Charles agrees with him that Iran should never have nuclear weapons. But that reckless comment, like so many presidential statements in the last month, simply floated into the ether after persuading no one.

The next day brought a visit to New York, and a busy schedule that included visits to the 9/11 Memorial, an urban farm in Harlem, the New York Public Library, and an evening gala.

The only glitch occurred when New York’s charismatic young mayor, Zohran Mamdani, suggested Britain should return the Koh-I-Noor, a huge and historic diamond appropriated by the British from a 10-year-old maharajah in India in 1849. It was an awkward moment, but it does raise a question: if the king had given a few of the crown jewels instead of an old bell to the bling-crazy president, who knows what he might have asked for in return? Nebraska? The entire United States? That would have been an interesting way to wrap up a visit designed to honor the American Revolution.

Before the visit, a friend of mine jokingly wondered if Americans would plan any “No Kings” rallies during the royal visit, to use the name of the anti-Trump protests held in October and March. But it turned out the royal visit was itself something of a No Kings rally, in that it reasserted many of the democratic values that undergird an old but troubled friendship.

The difficult issues have not disappeared: a reported US proposal to withdraw support for British sovereignty in the Falklands. Diego Garcia. British consumers paying exorbitant costs for gas and home heating. A war in Iran that will not end well, with most US goals unmet, American prestige damaged, and allies resentful of rough treatment from the Trump administration.

But the visit did a great deal of good, using soft power to rub the edges off these hard differences. In what is surely a good sign for Starmer, the president has begun launching tirades at Chancellor Friedrich Merz of Germany.

US-UK relations are clearly better at the end of April than they were at the beginning. For a happy 72 hours, the climate improved perceptibly, thanks to a king with a surprisingly sure common touch.

• Ted Widmer is a former presidential speechwriter, and the author of a forthcoming book in June, The Living Declaration: A Biography of America’s Founding Text (Library of America)