Why is it OK for Donald Trump to visit Paris, but not OK for him to visit London? Despite the famed “special relationship” between Britain and the US, the American president’s long-planned trip to the UK has been indefinitely postponed — largely because of the unstated fear that Mr Trump would be greeted by mass protests.

Instead, he has accepted an invitation to France — and could be seen happily reviewing the troops, alongside Emmanuel Macron, at the annual July 14 parade. The fact that the French president felt able to take a domestic political risk by inviting Mr Trump to Paris — despite the US president’s 14 per cent approval rating in France — offers some insights into the fine art of handing Mr Trump.

Mr Macron issued his invitation to the US president from a position of strength. His first encounter with Mr Trump featured a theatrical bone-crushing handshake. To some this might have seemed like the diplomacy of the playground. But it sent a clear message. France was not going to be pushed around. By contrast, Theresa May’s first visit to Washington featured the UK prime minister briefly holding hands with Mr Trump at the White House. To many in Britain, this looked like a cloying closeness with an unpopular US president.