There has been a subtle change of tone from Joe Biden and Boris Johnson about the likelihood of a Russian invasion of Ukraine. It has gone from ‘highly likely’ to ‘there may be a diplomatic solution’ — or from ‘almost all hope lost’ to ‘chink of hope’.

So from where does that hope emanate? Largely, I am told, from noises out of Ukraine that its government is moving towards a public statement that although it retains the right to join the Nato western defence alliance, it will commit to not consider applying for at least ten years.

The US president and UK prime minister are keen to encourage, through diplomatic channels, such a statement from Ukraine’s President Volodymyr Zelensky.

They hope that this would remove any powerful motive for Putin to move his 140,000 troops encircling Ukraine across the border, and begin a conflict that would probably endure for years, would be hugely costly in lives and Russian living standards, and for which Russian people have not been prepared.

Apart from anything else, Putin has already secured one important gain (in his terms) from threatening the integrity of the Ukrainian state: Biden, Johnson and EU leaders have tacitly accepted that Crimea, the region of Ukraine he illegally annexed in 2014, is now permanently part of Russia.

‘By threatening the rest of Ukraine, he has consolidated his hold over Crimea,’ said a government source. ‘No one disputes that’.

Putin has also — though too late in the day, some might say — succeeded in unifying what looked like a rabble response from western countries. The US, UK and EU are taking a collective approach to the punishing sanctions they would impose if Putin invades and there is now a rapid build up of Nato troops in the Baltic and close to Ukraine.

It is now clear, for example, that Germany will not open the important Nord Stream 2 gas pipeline from Russia to Europe if there is an invasion (though Germany is yet to formalise that). ‘It is the opposite of what Putin wanted,’ said a source. ‘Though our initial disunity was not helpful’.

As for the appearance of chaos in the so-called special relationship between the UK and US, which Putin will have been enjoying for months, that has also been dampened.

My sources tell me that at the end of their 40-minute call tonight, Johnson told the American president the UK wanted to do everything it could to help, and Biden responded ‘we’re not going anywhere without you pal’.

Maybe there is life in the West yet.