America’s enemies, by contrast, enjoy the presidential blessing (without offering him any gratitude in return). This is a good time to be a Cuban Communist, and the best moment since 1979 to be an Iranian ayatollah.

One must, of course, add that Mr Obama has been busy fighting climate change. When you are saving the planet, he suggests, there isn’t much time to deal with mere mass murderers, such as Isil. Despite his African heritage, the first black President seems more preoccupied than any other leader by what are known as “First World problems”.

So, for nearly eight years now, the leader of the free world has not led it – time enough to notice the unfavourable difference this has made to the global balance of power.

Which ought to help the European Union fill the vacuum. Nobody in Britain listens to Tony Blair these days, but his pro-EU intervention this week was typically clear and positive. He talks bad history when he says “Britain’s destiny is to lead in Europe”: Europe is perhaps the only continent which this country has never led, although we have stepped in from time to time to sort things out. But Mr Blair is surely right to call for “some passion” from the Remain side rather than all these dire letters to the newspapers from rich and famous people boasting about how well they are doing out of the system. Mr Blair would be much the best leader if the Remain campaign wanted to reach the general public.