“Training and teamwork,” he said. “When there’s an emergency, everyone knows what to do. If someone sees a way to solve a problem, they’ll speak up.”

I was still a bit dubious.

“But surely,” I said, “there comes a moment when you have to say...”

He instantly interrupted. Thrusting his imposing head forward, he fixed me with his ocean-blue eyes and rapped out: “Do as you’re fucking told! I Is that what you mean?”

“Er, yes. That would be it,” I said, perceiving in that moment one reason why this genial and cultured man had become one of the most senior people in the whole of the UK armed forces.

I call this the “F moment”, the point at which the discussion must be replaced by a direct instruction. We don’t have many F moments in school leadership. We tend to say, “Jack, would you mind looking after 10W after break?” Or, “Maggie, I wonder if you’d ask the caretaker if he’d mind talking to the cleaner in charge and ask if the lady who does my room could have a go at the windows? Thank you ever so much.”

The problem with this approach is that when you do give a direct instruction, it is often interpreted as the beginning of a debate. A Warwickshire primary head recalled telling a young teacher not to park on the grass. “He came up with reasons why he should park there,” said the head. “In the end, I just had to look him in the eye and say, ‘You’re making the mistake of thinking this is a discussion. It isn’t.’”

Mind you, even that approach can go wrong. A friend, a secondary deputy, told me gleefully of his head’s attempt to get the caretaker to clean the fly-blown light fittings in the hall.

“Yes, I’ll make a note...”

“No. Do it now.”

“Right. As soon as I’ve...”

“No. Get your ladder. Do it now.”

“Eventually,” said my friend, “the caretaker stormed up his ladder in a temper, fell off it, and was on sick leave for six months.”