PM's challenge is to see if usual rules of special relationship still apply after years of love bombing

Visits by prime ministers to the American president matter much more to us "Brits" than they do to them. Donald Trump spelt this out in the off-hand way he announced that he had granted Sir Keir Starmer the coveted appointment in his busy schedule. "We have a lot of good things going on," the president boasted. "But he asked to come and see me and I just accepted his asking.".

After his phone call with the prime minister, Trump declared "we're going to have a friendly meeting, very good". That was before Sir Keir publicly disagreed with Trump's ruling that Volodymyr Zelenskyy is "a dictator". Always assuming that his invitation is not cancelled in a fit of presidential pique, Starmer will find himself proceeding with the utmost caution when he gets to the Oval Office.

Downing Street sources say they are anxious "not to poke the bear" in the full knowledge that previous leaders have endured many awkward moments in their attempts to further a special relationship at away matches. Starmer will have his work cut out. Since his re-election, Trump has signalled that he has less time than ever for traditional alliances.

Newly inaugurated presidents traditionally send friendly greetings to their territorial neighbours. Trump slapped tariffs on Canada and Mexico and talked about US territorial expansion to both the north and the south. Historically the UK prime minister has often been the first foreign leader welcomed by a new US president. Trump hosted Theresa May less than a week after he took office for the first time and surprised her when he held her hand to go down some steps.

This year Starmer has already been preceded by the leaders of Israel, Japan, Jordan and Indonesia and will be crossing the Atlantic to pay his respects in the same few days as France's President Macron. Thatcher and Reagan's political romance. Even at the best of times, British officials are prone to exaggerate the closeness of the two countries' mutual interests.

Harold Macmillan thought he could teach the young John Kennedy a thing or two, as the Greek to JFK's Roman, but ended up being dictated to by Kennedy on the nature of the UK's "independent" nuclear deterrent. One of the wily Harold Wilson's most significant achievements was refusing to send British troops to fight alongside the Americans in the Vietnam War.

The most celebrated PM/POTUS political romance was between Margaret Thatcher and Ronald Reagan. Indeed when the Falklands conflict broke out in the spring of 1982, I was in the White House briefing room to hear then US secretary of state Al Haig joke with innuendo about the closeness of their relationship.

It blossomed after Thatcher won Reagan over to give the UK expedition staunch support, in defiance of the advice from some of his officials. Even so, Thatcher was unnerved by Reagan's apparent willingness to consider mutual nuclear disarmament in discussion with the Soviet leader Mikhail Gorbachev in 1986.

She flew hastily to Washington DC following the Reagan-Gorbachev summit in Reykjavik - "to give Reagan a bollocking" - at least according to the Daily Express reporter in her travelling party. In 1990 she reportedly told George HW Bush "now George, this is not time to go wobbly" during the flurry of meetings and phone calls which followed Iraq's invasion of Kuwait.

Clinton owing Blair and Bush's love bombing. John Major got off to a bad start with Bill Clinton after Conservative sources tried to help the Republican campaign dig up dirt on Clinton's time as a student at Oxford. Soon after the US election in 1992, Major flew to the US in the hope of being invited to a face-to-face meeting with the then president-elect. After several days all he got was a phone call from Little Rock, Arkansas.

In spite of their ideological closeness, Tony Blair later said he found it more difficult to deal with the Third Way Democrat Bill Clinton than he did with the "straightforward" Republican George W Bush. Clinton nonetheless was a key player in bringing about the Belfast agreement. Blair's greatest success was persuading the president to commit US forces to peacekeeping in the Balkans but he also did Clinton significant personal service.

Blair went on a scheduled visit to the White House at the height of the Monica Lewinsky scandal, just days after the president had made his statement "I did not have sex with that woman". At their joint news conference afterwards, Blair allowed all the questions to be deflected to him and expressed his admiration for the president. As they walked away from the East Wing, Clinton put his arm around the prime minister and appeared to say "I owe you one".

Clinton's advice to Blair on his successor George W Bush was "hug him close". But both sides were apprehensive when the Labour prime minister flew to Camp David for his first meeting with the second President Bush. Bush wanted them to dress casual, and according to the British ambassador, Blair put on some "ball-crushingly tight jeans". From Bush's first words about sharing the same kind of toothpaste, Blair was subjected to love bombing.