With a Letter From King Charles, Starmer Was Welcomed Into Trump’s Court

King Charles III was not in the Oval Office on Thursday afternoon. But his regal presence loomed over the meeting between President Trump and Prime Minister Keir Starmer, which felt at times less like a big-power showdown over Ukraine than a courtesy call between two Renaissance royal courts.

From the moment Mr. Starmer pulled an embossed letter from his breast pocket and handed it to Mr. Trump, with an invitation from the king for the president to make a state visit to Britain, the much-anticipated encounter between these two leaders relaxed into something friendlier, but also somehow less momentous.

“A beautiful man, a wonderful man,” Mr. Trump said, after poring over the two-page letter, which was signed “Charles R” in a bold, oversized hand not unlike that used by the president to sign dozens of executive orders.

It fell to Mr. Starmer to explain the diplomatic novelty represented by the invitation: Mr. Trump is the first elected leader in the modern era to be honored with two state visits to Britain. “This is really special,” Mr. Starmer told the assembled press corps. “This has never happened before.”

The prime minister might have added: Never has an elected British leader deployed the monarchy so transparently to win the favor of another head of state.

Mr. Starmer is well aware of Mr. Trump’s enchantment with the royal family. The president viewed his last state visit in 2019, during which Queen Elizabeth II threw him a lavish banquet at Buckingham Palace, as a highlight of his first term. Mr. Trump has lately taken to referring to himself in royal terms: “LONG LIVE THE KING!” he posted on social media, after moving to kill New York City’s congestion pricing program.

With Mr. Trump on the brink of an epochal split with Britain and the rest of Europe over how to deal with Russia’s war on Ukraine, Mr. Starmer apparently calculated that a little royal stardust might bridge the gap — or at least paper it over.

On some counts, he seemed to have succeeded.

Mr. Trump gave Mr. Starmer little comfort on his biggest ask: that the United States provide a security “backstop” for British and European troops that could keep the peace after a potential Trump-brokered settlement between Ukraine and Russia. But he won Mr. Trump’s endorsement of a deal relinquishing British sovereignty over a string of strategically important islands in the Indian Ocean. And he got a welcome sign that Britain might wriggle out of American tariffs.

Back home, Mr. Starmer won praise, even from the normally antagonistic right-wing press. “What an Unlikely Bromance!” The Daily Mail said. “Special Delivery,” said The Sun, over a photo of a tickled Mr. Trump showing off the invitation from Charles. “Keir’s Trump Card,” said the more reliably friendly Daily Mirror.

Given all the ways that the meeting could have gone wrong, Mr. Starmer returned to London with a tidy political victory. Mr. Trump’s apparent approval of his deal to hand over the Chagos Islands to Mauritius in return for the right to keep operating a British American military base on Diego Garcia, will deprive the opposition Conservative Party, as well as the right-wing disrupter Nigel Farage, of a major talking point against Mr. Starmer’s Labour government.

Mr. Starmer also got credit from Mr. Trump for arguing his case on why Britain should be spared the tariffs that Mr. Trump appears ready to impose on the European Union. The president said he expected Britain and the United States to strike a trade deal that would make tariffs unnecessary.

“He was working hard, I’ll tell you that,” Mr. Trump said, after Mr. Starmer lobbied him over a lunch of salad, grilled sea bass and chocolate caramel cake. “He earned whatever the hell they pay him over there.”

Still, on the most critical item on Mr. Starmer’s agenda, the prime minister made little headway. Mr. Trump brushed aside questions about whether the United States would provide a security guarantee to Ukraine to prevent President Vladimir V. Putin of Russia from launching another invasion. Mr. Trump insisted Mr. Putin would “keep his word” if a peace deal was reached.

The presence of American workers in Ukraine, Mr. Trump added, presumably there to help extract the rare-earth minerals that President Volodymyr Zelensky of Ukraine has agreed to share with the United States, would be an insurance policy to prevent Russia from attacking Ukraine again.

Asked if he would come to the aid of British troops if they were targeted by Russia in Ukraine, Mr. Trump equivocated. “I’ve always found about the British, they don’t need much help,” he said. “They can take care of themselves very well.” Then he added, “If they need help, I’ll always be with the British, OK?”

That fell short of Mr. Starmer’s hope for an ironclad American security guarantee. But like President Emmanuel Macron of France, who met Mr. Trump on Monday, Mr. Starmer was determined to avoid a public split with the president over the issue. He lavished praise on Mr. Trump for his peacemaking efforts, adding only that it “can’t be peace that rewards the aggressor or that gives encouragement to regimes like Iran.”

Fresh from announcing a landmark increase in military spending and back in London, where he will play host Sunday to a meeting of 18 leaders to discuss Ukraine, Mr. Starmer has rebranded his premiership. No longer is he defined solely by his failure to jump-start Britain’s torpid economy.

“The first few months of the Labour government were confusing for a lot of people,” said Steven Fielding, a political historian at the University of Nottingham. “In a sense, this has given him an identity as a patriotic leader who supports Ukraine and who is willing to stand up to Trump and Putin.”

And yet, at the White House, Mr. Starmer was so solicitous that he appeared at times to be less a world leader than a well-mannered messenger for one. When Mr. Starmer was asked by a reporter what he made of Mr. Trump’s desire to annex Canada — of which King Charles is the ceremonial head of state — he replied, “I think you’re trying to find a divide between us that doesn’t exist.”

“That’s enough, thank you,” said a clearly irritated Mr. Trump, cutting off the reporter and gesturing for the next question.

Earlier, in the Oval Office, Mr. Starmer dutifully performed his role as a courtier for the king. It was a strange turn of events for a Labour leader who once told a filmmaker, “I often used to propose the abolition of the monarchy.” He has long since disavowed such statements as youthful indiscretions, and even has a knighthood that was bestowed by Charles.

Sir Keir, taking back the letter from Mr. Trump, said that the president’s last state visit had been a “tremendous success” and that “His Majesty the king wants to make this even better than that. So, this is truly historic.”

“What I haven’t got yet is your answer,” Mr. Starmer added, laughing anxiously as he perched on his chair next to the president.

“The answer is yes,” Mr. Trump replied, drawing out the words as he turned to the forest of cameras and microphones. “On behalf of our wonderful first lady, Melania, and myself, the answer is yes.”