Then there’s this one on the zany new world of Zoom diplomacy:

Legend has it that in a room in Number Ten one such special telephone sat unused, to the point where no-one could remember why it was there. One day to the shared consternation of both Prime Minister and Private Secretary who happened to be there – it rang!

The Private Secretary picked it up:

Hullo?

Just testing!

*Sound of phone-call being terminated*

And they were none the wiser …

Today, the astonishing results of Moore’s Law (the prediction that the cost of repeated doubling of computer-chip power would tumble) have compounded up over some 30 years. Videos now work smoothly, to the point where family WhatsApp chats across the planet are in effect free. Far-flung diplomats typically talk easily with each other or with the Ministry by video link from secure mobile phones.

This, of course, reopens the questions that keep popping up in the cynical minds of hard-pressed finance ministry officials:

What is diplomacy anyway?  We agree, it’s all about direct serious government-to-government talking. But do we really still need old-fashioned diplomats and all those expensive overseas buildings and cars and entertaining and other useless flimflam?

We now have awesome communication kit unavailable in times past. Why can’t governments just talk to each other directly, whenever they like?

Of course, you pampered diplomats insist that talking is far better to do face-to-face. Guess what? That’s what Zoom and Teams let us do, almost for free!

The problem with Zoomy-type online discussions is that the format is weirdly ultra-democratic. There’s no sense of occasion. There is no ‘occasion’. No buzz in the room as everyone waits for a famous keynote speaker. No sense of shared surprise when a speaker says something provocative. No sense of shared energy and amusement.

Instead, everything is down to you and your screen that itself might be just a few square inches on a mobile phone. Authority and any sense of commanding presence drain away. You don’t need even to pretend to listen to anyone. You can turn off your camera and stroll away for a cup of coffee, pleading a bad connection or a knock at the door. The most powerful leaders on earth shrink down, just another postage-stamp sized face droning away on one part of your screen. It’s all so flat. No-one cares.

Here’s the key point.

So many people during the COVID-19 lockdowns have failed to grasp the obvious fact that video meetings have to be done differently. Your PowerPoint slides were pretty bad even for live events: now they are just unreadable on a small screen.

To capture and maintain attention when your audience is with you on all sorts of platforms and screens, you need a quite different style and quite different content. Everything needs to be simplified and subtly exaggerated. Far better to say a few big things and then stop than your usual longer list of clever smaller things.

This is why to be useful any significant international event such as COP26 will continue to need to be done ‘live’, with actual humans breathing in their myriad shared germs and viruses and bacteria.

You just can’t generate any sense of urgency or importance via online events. A leader committing to expensive and maybe unpopular climate programmes needs to be there in the room with colleagues. To look directly at those colleagues in their eyes, to get that irreplaceable visceral sense of how far (if at all) those other leaders are likely to be trustworthy as they too sign up. And then to have that all-important quiet word in the corridor with a key ally afterwards, to agree how issues will be handled going forward.

How all that is to work on the day needs actual diplomats there at the conference centre beforehand, working out how to help their leaders meet the right people at the right time and avoid the wrong people all the time.

Sure, lots of this can be done in advance remotely. And sure, lots of useless expensive process drawn from ages long gone might be dropped.

But in dropping useless expensive old process, let’s not replace it with useless expensive new process. The more so if the very nature of the new format means that no-one takes the discussions seriously. That no-one is really committed to what’s agreed.