Special US-UK relationship? It depends on Donald Trump's mood when he wakes up

Phew! We're friends again. The warm, reassuring words of President Trump at Davos will be music to Theresa May's ears.

The President said the US and the UK were "very much joined at the hip". He didn't actually use the word "special" - Mrs May did that. But he said it was a "really great relationship".

Since Theresa May rushed to Washington a year ago to pay homage at the court of King Trump, things haven't exactly gone smoothly.

Mr Trump has tweeted criticism of British intelligence services over terrorism and re-tweeted posts from the far-right organisation Britain First. He then cancelled a trip to open the new US embassy in London, criticising its cost and "off" location.

It was all a bit disingenuous. The truth is that Mr Trump's team feared any visit would be mired by protests.

But it is also true that America is turning away from the "special relationship" and has been for some time.

For instance, President Obama was far more concerned with his relationship with Europe than Britain specifically.

It has been noted by British diplomats that the first state visit to Washington of a foreign leader will not be Mrs May but rather Emmanuel Macron of France.

And although the two leaders in Davos agreed to finalise details of a planned visit to the UK later in the year, don't be surprised if it is not a state visit or even doesn't take place at all.

As much as he would love the red carpet treatment and the pomp and ceremony, Mr Trump won't want demonstrations everywhere he goes.

In America they'll be running into the crucial mid-term elections and so he will have the perfect excuse to stay away if he wants to.

There is also the delicate issue of the Royal Wedding in May. It is very difficult to see Prince Harry inviting Donald Trump to his nuptials

It is all pretty awkward for the Prime Minister. A post-Brexit Britain will need America more than ever, just at the time when America is turning away from the special relationship.

That's why President Trump's words on trade will be especially reassuring to Mrs May.

"Trade is going to increase many times and we look forward to that", he said.

Talks have begun on a post-Brexit trade deal, but they will not be easy. There are many hurdles to negotiate before Britain gets anything like what it wants or needs.

The relationship is being tested in other ways. Mr Trump's decisions to pull out of the Paris climate change deal, to threaten to wreck the Iran nuclear agreement and to move the US embassy from Tel Aviv to Jerusalem have all irked British diplomats .

But the obsession about whether the relationship is special or not is a very British thing. I haven't heard many Americans even mention it. I'm not sure they know it even exists.

Critics say Mr Trump's tweets suggest he will not be a reliable partner for Britain. He will have only America's interests at heart - or so the theory goes.

I am not so sure.

He knows there are deep ties and he knows they will outlive his presidency.

He also knows Britain remains America's most reliable ally. There is close co-operation on surveillance, security and military matters and both sides recognise the importance of that.