LONDON — President Donald Trump has arrived in the U.K. for a pomp- and ceremony-heavy visit to commemorate the 75th anniversary of D-Day already having achieved some measure of success in his twin quests: for disruption and acceptance.

Before departing, Trump injected himself into British domestic politics, endorsing nationalist-leaning former London Mayor Boris Johnson in the dozen-candidate Conservative Party race for prime minister and urging the country to exit its Brexit negotiations if its demands aren't met by the European Union.

In the U.K., Trump is a deeply controversial figure — some politicians on the left are boycotting him — which means his decision to wade into the intra-party prime minister fight could be helpful to Johnson now but an irritant for British swing voters in the long run.

He also referred to Meghan Markle, the duchess of Sussex and a granddaughter-in-law of Queen Elizabeth II, as "nasty" in an interview with a British newspaper — a comment he denied making despite the existence of a clear audio recording.

And yet there is so much on the line for a beleaguered Britain right now — destabilized by the paralysis following its Brexit vote three years ago to leave the European Union — that Trump can still expect the literal and figurative royal treatment from the queen and her family. While it has been on the books for some time, Trump's first official "state visit" to the U.K. couldn't come at a more auspicious moment for British officials eager to show that their "special relationship" with the United States is as strong as ever.

In short, they need him, and he knows it.

That could make for some more interesting theatrics, in terms of both Trump's forays into British politics and his willingness to talk about his leverage in the bilateral relationship. But it might not amount to much in terms of deal-making, even though Trump could benefit from showing progress on the international stage amid trade disputes with China and Mexico, the resurgence of North Korean nuclear testing and heightened tension with Iran.

"I do think this trip is going to be heavy on ceremony and light on substance," said Amanda Sloat, a senior fellow at the Brookings Institution who previously worked on U.S.-Europe relations in President Barack Obama's State Department. That's in large part because Prime Minister Theresa May, who will meet with Trump on Tuesday, is stepping down as Conservative party leader on Friday.

In some cases, Trump seems to relish adding to the atmosphere of upheaval. His interviews with newspapers associated with right-wing publisher Rupert Murdoch in the days leading up to the trip produced a steady stream of headlines in the U.K. that roiled local politics and culture — from his endorsement of Johnson to his thoughts on Brexit to labeling Markle with a word, "nasty," that he's also used in conjunction with his 2016 rival, Hillary Clinton, and 2020 Democratic presidential hopeful Kamala Harris.

Beyond the sensational, Trump has been talking about a possible U.S.-U.K. trade deal for more than a year, and some in Britain think his presence here could be important for another topic that gets less attention but is very important: international security.

"We want to have that direct conversation with the president on everything from China to Iran to North Korea," said a former adviser to ex-Prime Minister Tony Blair, who spoke on the condition of anonymity to avoid upsetting his current employer. "One of the reasons that direct contact with this president is so crucial is that it's the only way of really trying to know what the administration game plan is. All the usual structures and processes of diplomacy really don't work with this administration because of the president's personal style."

In addition to May and the royals, Trump plans to take a quick trip to Ireland to meet with Taioseach Leo Varadkar, who is head of that nation's government, and sit down for a one-on-one with French President Emmanuel Macron.

All of it will play out against the backdrop of the anniversary of D-Day — June 6, 1944 — when Allied forces launched a surprise attack, establishing a beachhead at Normandy, France, and turning the tide of World War II in Europe. At the time, the United States and the United Kingdom were joined in their efforts to stop the expansionist nationalism of Nazi Germany.

Trump is expected to participate in ceremonies celebrating the anniversary Wednesday on the British side of the English Channel and Thursday at Normandy.

U.S. officials say the timing of Trump's trip, although it was long-planned, illustrates that it's the bond between the countries — not the personalities — that matters.

"Even in the most difficult times, where you may have political upheaval and uncertainty," a senior administration official said, "we need to stand together shoulder to shoulder."