David Frost – chief Brexit negotiator, Lord Frost – will not be National Security Adviser after all, Number 10 has confirmed. He had been appointed last year but will now not take up the post. Instead the key role as chief adviser on national security will go to Sir Stephen Lovegrove, currently Permanent Secretary at the Ministry of Defence.

There is some glee over this development – from establishment technocrat quarters and the more pro-EU, Jacobite-style, ultra-Remain types in the foreign policy community. A pro-Brexit person, the former diplomat Frost, has been dished, runs the line. The system has won and the securocrats have whacked a Brexiteer. The NSA post goes to a Perm Sec. The empire strikes back and all that.

But is that what’s really going on here?

No, the story is more interesting than that – a murky tale with its roots in the unwinding of the explosive, high-energy Dominic Cummings era.

The truth is that Frost himself was never enthusiastic about the NSA posting, say friends. And with Dominic Cummings now gone, Boris had an easy route for everyone to get Frost out of it.

“David didn’t really want the job. It was Cummings at his most disruptive trying to shake up the national security remit, to put in an outsider. Now Cummings is gone and David doesn’t have to do it. Relief all round,” says a Whitehall source.

Cummings was concerned for example that Britain’s nuclear capacity is crumbling, and he wanted someone fresh to get to grips with that and other problems.

Frost, say friends, is relieved to be decompressing after the Brexit negotiations – a seven day a week, round the clock slog.

Instead of the NSA gig, Frost is being given the title of UK’s Brexit and International Policy Representative. Critics say this is a classic Whitehall made up non-job title to sideline him.

“No, it is about beefing up the international policy function of Number 10 so that Number 10 doesn’t try to run everything but can set direction,” says another Whitehall source.

The criticism of the original decision to appoint Frost rested on his lack of national security experience, although Lovegrove is not a national security specialist either. But he has been at the heart of the MoD since 2016. Before that he was at the Energy and Climate Change department, and before that he was in the City. He is a former banker who spent ten years at Deutsche Bank.

This Frost-Boris-Lovegrove episode is another example of the process of “normalisation” post-Cummings and post-Brexit, as the politicians, advisers and officials look belatedly to re-establish a less explosive way of running the government.

Presumably Cummings himself will have something interesting to say about all this and more at some point soon.