Instant invitation to cement special relationship
I was watching live pictures of David Cameron walking into No 10 when we were told that President Obama was about to phone him. That's pretty quick. The phone call was also an instant invitation: the president said he and Michelle wanted to invite Mr Cameron and Samantha to Washington in July.
The two men will have already met a little to the north of here, in Canada at the G8 and G20 in June. Remember how long Gordon Brown had to hang around before getting an invite.
It may be that the president likes the cut of the new man's jib. But I tend to think that the White House has learnt that the British can be touchy allies, and it costs nothing to be nice. Mention the special relationship and the White House tends to groan. They still remember the fuss about the president only managing to squeeze in a meeting with Gordon Brown while walking through the kitchen of a New York hotel.
In the call to the new prime minister, the president lavished praise on the special relationship, talking about his deep and personal commitment to it, that the United States had no closer friend and ally than the United Kingdom, and how it was a bond that lasted for generations and across party lines, and which he hoped would thrive.
All this may be so, but the president's people also know the British press get awfully upset if they don't hear some such reassurance at regular intervals. It is one of those curious things about the president that while his whole foreign policy is based on the idea that the world needs to be reassured of America's friendly intentions, he doesn't seem to have particularly warm relationships with any foreign leader.
In that respect he's almost a mirror image of George W Bush, who didn't seem to care what people thought of his policy but was keen to slap backs and exchange quips. Perhaps Obama thinks it's time he had a chum on the world stage.