No pictures, please. It is not often that a British prime minister plays hide-and-seek with a US president. Custom demands they doff their caps in deference to the prized “special relationship”. Boris Johnson, though, faces an election. He knows his American soulmate Donald Trump, in Britain for the Nato summit, is unloved by voters. Mr Trump was uncharacteristically forgiving as his host darted to and fro to avoid the cameras.

This tableau was, in its way, a metaphor for this week’s grand Nato gathering. Marking its 70th anniversary, the 29-nation alliance might have worked on a vision for the future. The founding plan — to keep the Americans in, the Soviets out and the Germans down — could do with updating.

Instead, the event was scripted as an exercise in diplomatic damage limitation. Atlanticism is said to be in crisis, caught between a capricious US and miserly Europeans. And a public spat between Mr Trump and French President Emmanuel Macron dispelled the notion of an alliance advancing as one.