When Boris Johnson finally enters No 10 one of his first calls will likely be to President Trump, a political soulmate and fellow Brexiteer who has been talking up Johnson to become prime minister for a while.
After the congratulations, Johnson will have to ask the big question: how quickly can the US and the UK reach a trade deal to soften the blow of a no-deal Brexit?
At which point, Johnson will experience what everyone who deals with Donald Trump experiences: the sudden vanishing of the ground beneath them. Whatever Trump said one year, one month or even five minutes before no longer matters.
For him, every negotiation involves winners and losers, and any country pleading for a deal will look like easy prey.
Forget about the state visit, dinner with the Queen and tea with Prince Charles. Ignore all the cheerleading he did for Nigel Farage and Brexit. If the UK cannot come up with terms that benefit the US, then Johnson can forget about it.
Trump is not a man to do favours out of nostalgia for some special relationship he had nothing to do with creating.
It is going to be a sharp awakening for the new Johnson government, which will seem to be banking on some deep transatlantic love-in to save them from international isolation.
For some time now, British Conservatives and American Republicans have been watching Johnson and Trump running towards each other in slow motion, like lovers on a beach, waiting for that final embrace.
Both men are more popular with voters than with their political colleagues. Both have flyaway hair, and communicate in unique and vivid ways — far more colourfully than most politicians.
Trump shows off with his wealth the way Johnson does with his education. Both enjoy tweaking European leaders.
Johnson criticised Trump’s attack on congresswomen of colour but did not call the President’s remarks racist
They have each had complicated personal lives. Johnson has been married twice, Trump three times. Both have had well-publicised extramarital affairs.
Yet behaviour which would have ended the careers of most public figures seems only to have increased their appeal.
To those who love them, their flaws seem to make them only more credible as leaders capable of addressing people’s ordinary concerns.
This week, The New York Times analysed Trump’s appeal to Republicans in Washington, who have all but given up opposing him in public: “Republicans may cringe at some of Mr Trump’s crude comments and insults. They may wince at his easily unmasked falsehoods.
"They may roll their eyes at his lack of understanding of government fundamentals. To many, his personality itself is off-putting. But he is now their guy.”
Conservatives who may dislike Johnson will rally round as long as he retains his popularity within the party at large, just as Republicans have learned to tolerate Trump.
Both men saw their path to the highest office lay in veering out to the Right, then launching a missile at the establishment. They are both equally ready to be loathed as much as adored.
But where could this relationship ever go beyond flirtation and mutual admiration?
Chancellor Philip Hammond said this week that it is unrealistic that the US and UK could strike a trade deal within months of Britain leaving the EU.
The International Trade Secretary, Liam Fox, echoed Hammond’s concern, saying this was not even a deal for Trump to negotiate and sign, given that so much trade policy is handled by individual US states, not the federal government.
Fox also pointed out that under EU law it would be illegal for the UK to negotiate with the US until it has left the European Union.
Add to that next year’s presidential election, which will hog the attention of America’s political class, and the chances of an expedited US-UK deal look slim to non-existent.
If that is the case, or if Trump were to lose the election, then Johnson’s decision to align himself with the President looks ill-advised.
Trump won’t roll over because Johnson is a kindred spirit — his party thinks the US has little need for allies
The recent fiasco around Sir Kim Darroch’s resignation as Britain’s ambassador to Washington showed how tongue-tied Johnson becomes when the subject turns to Trump.
Whereas Jeremy Hunt stood up for Sir Kim when Trump called him “a pompous fool”, “wacky” and “very stupid”, Johnson equivocated, prompting the ambassador to quit.
Johnson was more decisive this week, after Trump said that four congresswomen of colour should “go back” to the countries “from which they came” if they were so critical of America and him.
Johnson called Trump’s attack “totally unacceptable in a modern, multi-racial country you’re trying to lead”, but declined to call the President’s remarks racist.
Expedient as it might be to avoid incurring Trump’s Twitter rage, Johnson’s delicacy risks rebounding on him.
David Remnick, the editor of The New Yorker, wrote yesterday of the passivity within Trump’s own party: “What’s curious is just how many people have resisted seeing squarely Trump’s racism, his shrewd exploitation of animosity, hatred and division for political advantage.”
Remnick warned that those who vote for Trump, or even tolerate him, “will have to ask themselves what it means to overlook his racism and what this says about them.”
Other foreign leaders have tried seducing Trump, notably President Emmanuel Macron of France and Prime Minister Shinzo Abe of Japan.
Their results have been mixed. Macron hoped a close friendship might elevate France’s global status, but he is reported to have given up.
Abe strove to be closer to Trump than any foreign leader. They play golf together and talk regularly on the phone. Abe even wrote to the Nobel Peace Prize committee to press Trump’s case for the award.
When Trump visited Tokyo in May, Abe smothered him with flattery and staged events designed to appeal to Trump’s taste.
He inaugurated a gigantic President’s Cup trophy at a sumo tournament, which Trump presented to the winner.
He arranged for Trump to be the first foreign leader to meet Japan’s Emperor Naruhito.
He persuaded Trump to visit Tokyo by telling him that a new emperor in Japan is a “100 times bigger” event than the Super Bowl.
But to what end? Trump has still raged about Japan’s trade surplus with the US and threatened potentially damaging tariffs on Japanese cars. His wooing of North Korea’s Kim Jong-un continues to unsettle the Japanese, who could be in range of North Korea’s nuclear missiles.
Nothing has been achieved yet, though Japan is not yet engaged in a full-blown trade war with the US, the way China is.
There is now talk that a minor US-Japan deal might be struck in September, but it has come at a high cost to Japan’s dignity.
Johnson could suffer a similar fate. Trump has weaponised tariffs in an attempt to make Canada, Mexico and even China grovel. He believes protectionism is maximising US economic growth, even at the cost of global trade.
There will be major obstacles in the path to a US-UK trade deal, from food hygiene standards to giving US companies access to the NHS.
Trump won’t roll over because he thinks Johnson is a kindred spirit. He would rather pry open the UK market for American firms.
Most Republicans share Trump’s view that America has little to gain from friendship with its international allies. Even Britain.
They see these relationships as purely transactional. If there is nothing in it for America today, Trump won’t pretend for the sake of a fleeting political kinship.