American secretaries of state can be earnestly dull, like John Kerry, or plain brilliant, like George Marshall; they can be Machiavellian, like Henry Kissinger, or intensely political, like Hillary Clinton. Mike Pompeo, the bluntly spoken, present-day incumbent who will discuss “shared global priorities” with Theresa May in London, is simply a problem.

As last week’s failed US pressure tactics in Venezuela showed, the former army officer, Christian evangelical and ex-CIA director favours a muscular approach to diplomacy. His messianic drive to force regime change in Iran is another example. He recently suggested Donald Trump had been sent by God to save Israel from Tehran’s mullahs.