Nevertheless, there will be those in the Foreign Office who believe Darroch should not be punished for writing in private what most members of the White House staff would agree to be virtually a truism.

They also regard the leak and the suspiciously coordinated attack on the neutrality of the civil service by Nigel Farage as a moment to dig in and defend the integrity of their profession. The populists’ long, destructive march through the institutions was never likely to stop at Whitehall, and now they know the wrecking ball has reached the Foreign Office.

The mood in the department will turn on events in the next few weeks, providing an early test for a likely Johnson premiership on how he sees his relations with the civil service, with America and with the domestic Brexit movement.