A blimp is prepared for scheduled protests during President Trump’s visit to Britain. (Matt Dunham/Associated Press)
Geoffrey Wheatcroft is an English journalist and author. His books include "The Strange Death of Tory England," and "Yo, Blair!"

BATH, England — Although many American presidents have paid visits to England, there has never been a visit quite like Donald Trump’s this week. But then, has there ever been a president quite like him?

Almost as soon as Trump was inaugurated, the British prime minister, Theresa May, rushed to Washington to meet him, with what many of her compatriots thought unseemly haste. It wasn’t made better when they embarrassingly held hands and were photographed in the Oval Office with the bust of Sir Winston Churchill between them.

They exchanged the usual platitudes about the special relationship, or what the former German chancellor Gerhard Schroeder rightly called the relationship so special that only one side knows it existed. The prime minister extended an invitation to Trump to pay a state visit to London. This is something presidents have enjoyed only late in their terms, or in some cases not at all, but the prospect of driving down the Mall in a gilded horse-drawn coach to a magnificent banquet at Buckingham Palace delighted Trump.

Alas, by now his unpopularity in Britain is so intense that he can barely show his face in the streets of London, and this is well-nigh a private visit. Trump will be helicoptered from the American ambassador’s residence in Regent’s Park to the prime minister’s country residence, Chequers, both heavily guarded, and to Blenheim Palace, the birthplace of the president’s supposed hero, Churchill.

The curious nature of the visit could be highlighted by the official absence of the one British politician Trump seems eager to see, and who may return the eagerness, although it’s not clear what they have to give one another, apart from bromantic mutual admiration. “Boris Johnson,” said  Woody Johnson, the American ambassador in London, “has been a friend of the president,” with whom he has “a warm and close relationship.” This might seem improbable, given the two men’s backgrounds — the spoiled, notably unintellectual child of a property millionaire versus the clever English boy (albeit born in New York City and of partly Turkish and partly Jewish descent) educated at Eton and Oxford — but there may be some truth in it.

Until this week, Johnson was foreign secretary. He attended May’s crisis cabinet meeting at Chequers and offered her his full support. Three days later, he resigned, taking care to make it a photo op, with the picture of him writing his resignation letter released to the media. If he’s trying to supplant May, this combination of cynicism, inconsistency and sheer disloyalty could not have helped his chances. Nor will meeting Trump obviously endear Johnson to the British public, although Johnson might see it as a way of further destabilizing May. And, come to think of it, Trump might like that, too, given the way he has gloated over the British government’s “turmoil.”

Despite the superficial gulf between the coarse New York real estate tycoon and the silver-tongued classics scholar, between the author of “The Art of the Deal” and the author of “The Churchill Factor,” there may be a real affinity (and not just because of the hair-raisingly awful treatment of women they have in common). And that affinity could paradoxically help explain just why the “special relationship” is such a fantasy.

Two years ago, Johnson threw his weight behind the “Leave” campaign in the Brexit referendum, to decisive effect, many people think. Characteristically, he wrote two columns for the Daily Telegraph. One argued for “Remain” and one for “Leave.” At the last moment, he tossed a mental coin — or rather, one may suppose, he decided which would better advance his personal ambitions.

At that time, Johnson had an adoring personal following, although it has always been notable that he is loved most by those who know him least. Sir Max Hastings, the journalist and military historian, was editor of the Telegraph when Johnson worked for the paper. He has said of Johnson that “scarcely anybody who knows him well trusts him.”

The Brexit referendum was just over two years ago, in June 2016. Then came the upset of November, the election of Donald Trump, which many people found and still find as hard to believe as Brexit. Since then, quite apart from his egregious conduct over immigrants, his glad-handing with Kim Jong Un and Vladimir Putin, and his derision of NATO, Trump has never missed an opportunity to say what a good thing Brexit is, which is none of his bloody business. His enthusiasm for Brexit isn’t because Trump feels any deep love for British tradition, but because he hates the European Union as a competitor. And he can scarcely be bothered by what looks like Russian interference in the referendum since he was almost certainly helped by Russian interference in his own presidential election.

The worst thing of all about so many of the leading Brexiteers like Johnson was that they campaigned for Leave out of cynical calculation of advantage within the Tory party, but they never expected to win, and they had no idea what to do if they did. That has become clearer with every day that has passed since the referendum, and the more Brexit turns into a monumental train wreck, the more hysterical the Brexiteers become.

Three years ago, Johnson said that Trump was “clearly out of his mind” and that he was displaying “a quite stupefying ignorance that makes him, frankly, unfit to hold the office of president of the United States.” Recently he has taken to singing the president’s praises, and comparing him favorably with May.

By doing so, he does inadvertently perform a service — and so does Trump when he boorishly intervenes in British politics. As Hastings has said, Churchill invented the concept of the special relationship for reasons of political expediency, and was then the first of many prime ministers to find that it didn’t exist. Above all, it rested on a denial of reality: The reality that the United States, like all great powers in history, will in the end follow its own interests and objectives, with no regard for the interests and objectives of its supposed friends, let alone those of its avowed enemies. (Consider the Iraq War, when the relationship was embodied by President George W. Bush and Prime Minister Tony Blair.) If the presidency of Donald J. Trump teaches my country that lesson at least, it will be a small benefit.

Long ago, Churchill told the French general Charles de Gaulle that if he had to choose, he would always choose the open sea, and America, against Europe. After the war, ambiguity persisted in British policy, until we turned toward the continent 45 years ago, when the United Kingdom joined the European Economic Community. Now we’ve turned our backs on Europe again — and in the age of President Trump. What a time to do it!