• Donald Trump offered a rare apology on Friday after a public row with British prime minister Theresa May.
  • The US president was gushing towards May when the two met in Davos this week.
  • The prime minister appears to have secured a rare political surrender from Trump.
  • A state visit by Trump to the UK, which was put on hold last year, is now back on.

DAVOS, Switzerland – I am still puzzling over President Trump and Prime Minister Theresa May’s joint press appearance in Davos on Thursday.

While displays of mutual faith in longstanding alliances aren’t unusual at Davos (that’s the point of the entire World Economic Forum) this one was … weird.

Trump said he wanted to address the “false rumour” that he might not respect Britain, or May. And then he added, “We are very much joined at the hip when it comes to the military. We have the same ideas, the same ideals, and there is nothing that would happen to you that we won’t be there to fight for you, you know that.”

It was an odd thing to say given that there are no military threats to Britain right now, and the joint defence roles of the US and UK in NATO weren’t really in doubt.

The only way the meeting - staged entirely for the media - makes any sense is if you regard it as Trump trying to make peace, or even apologise, to May.

In the last few months, Trump has repeatedly insulted Britain and its elected leaders, by retweeting the far-right neo-Nazi group Britain First, by suggesting that London Mayor Sadiq Khan was weak on terror and by deriding the new US Embassy building in London for being in an "off location."

May didn't take this lying down. In November she said, "It is wrong for the president to have done this." His visit to the UK, planned for February was subsequently cancelled by Trump. It was an astonishing, high-level fallout given the longstanding special relationship between the two countries. When Trump is attacked he usually redoubles his insults against his attackers.

But not with May.

On Thursday, at his meeting with May, Trump seemed to take it all back, and on Friday he offered a rare public apology on ITV for publicising Britain First.

Hey presto! The president's visit is now back on, for a date later this year. Doubtless, there were many officials inside the Trump Administration who reminded the president that you cannot simply trash-talk your oldest allies if you want them to remain allies. And thus Trump has caved, a rare political surrender from the "very stable genius."

May appears to have tamed Trump. She is one of very few world leaders to have successfully brought him to heel (the other one might be Putin). Their Davos meeting might have been weird, but it counts as a diplomatic success for May.