The mood inside the British Residence is one of incredible sadness.
As I understand it, many of ambassador Sir Kim Darroch’s personal staff were in tears this morning.
And right across the UK diplomatic community in the USA, in our consulates and our UN mission, there is a sense of deep, deep disappointment.
Anger? Well, yes, that too.
Of course, towards the person who leaked the diplomatic cables.
But also towards the President of the United States, whose conduct is viewed as deeply disrespectful towards a key ally and good friend.
But here is another vital point: The Ambassador watched the entire ITV debate last night (not live, because he was in meetings).
And while Boris Johnson’s hesitation in backing him was a factor in Darroch’s resignation, it was not the main reason.
Sir Kim understood that he simply couldn’t do his job if he was frozen out of meetings with the President and senior White House officials.
Ultimately, he resigned not because of what Boris said but because he is a consummate professional and realised his position here was untenable.