JAN MOIR: As Prince's chief of staff departs after briefest of tenures... So why is it that few aides in Harry and Meghan's court have lasted longer than the gestation period of an elephant?

Three short months after he was hired as the man to guide Prince Harry through the next stage of his life, key aide Joshua Kettler is out.

He has moved on, gone with the wind, now visible only in the rearview mirror.

Kettler is yet another good man with an impeccable resume.

A senior staffer departed in the blink of an eye from the House of Sussex, leaving nothing behind except rumour, intrigue and the taint of something nasty in the Montecito utopia.

His unexpected exit as Chief of Staff follows a pattern established when Harry and Meghan were still part of the Royal Family and based in the UK.

Now, on both sides of the Atlantic, their record as employers stands as a curdled legacy of being unable to keep staff on board.

Prince Harry and Meghan with former chief of staff Josh Kettler, right, during a trip to Nigeria

Prince Harry and Meghan with former chief of staff Josh Kettler, right, during a trip to Nigeria 

For reasons unknown, the couple do not seem capable of maintaining the kind of vital support systems which have been key to royal survival since Tudor times and beyond – namely a devoted inner sanctum of trusted advisers and aides-de-camp who will ensure advancement both at court and with the public.

Why not? There have long been unsubstantiated rumours of difficult behaviour by the Duchess of Sussex, while the findings of a royal investigation into allegations of bullying were hushed up.

In today's victim culture it is all too easy to accuse a focused and forthright woman of being a bully when she is merely briefing staff and expecting the same high standards she demands of herself.

But the revolving door continues to whirl and the only people to survive long term on the Sussex payroll seem to be their devoted and dedicated team of lawyers.

These include Jenny Afia from top London firm Schillings, who once said of the bullying allegations against the Duchess: 'Knowing her as I do, I can't believe she would ever do that.'

Yet the Sussexes' troubled history as bosses tells its own story of difficulty and departure, with 18 staff leaving over a six-year period.

Perhaps that's not too many if you are an international conglomerate, but it's a huge number if you are simply a couple of – how can I put this? – philanthropically-minded opportunists whose commercial interests to date include producing 50 jars of strawberry jam, writing a whiny book, complaining about their lot on Netflix documentaries and accepting awards for being Best Prince Who Ever Lived, Number One Diana Son and International Duchess of Dior (Sample Size Please), not to mention being given the infamous Global Ribbon of Nonsense.

There have long been unsubstantiated rumours of difficult behaviour by the Duchess of Sussex, while the findings of a royal investigation into allegations of bullying were hushed up

There have long been unsubstantiated rumours of difficult behaviour by the Duchess of Sussex, while the findings of a royal investigation into allegations of bullying were hushed up

Yet tT18 staff leaving over a six-year period

The Sussexes' troubled history as bosses tells its own story of difficulty and departure, with 18 staff leaving over a six-year period

Whatever their role, few aides in Harry and Meghan's court have lasted longer than the gestation period of an elephant, but the truth is that most are out before a crested porcupine can pup, which is 90 days, if you are interested.

So what happened this time? We have been told that Joshua Kettler left by mutual consent. It was a trial period, sources told People magazine (a regular outlet for friends of the couple). And in the end, he simply wasn't 'a good fit'.

It was a different story back in May when Kettler was initially hired by the Sussexes as a Chief of Staff, which is rather a grand title to confer upon someone by a couple who are basically unemployed.

There was no talk of casual engagement or a trial period back then. All parties seemed to be committed; in it together for the long run.

Prince Harry was to be Kettler's primary charge, his chief role to help the exiled royal move on from the past and carve a bright and useful future. In this position he was to be an American version of a palace courtier – the men who Harry trashed without mercy in his memoir Spare, giving them disparaging nicknames such as The Bee, The Fly and The Wasp.

Like them, Kettler's task was to gently encourage the prince into making the right decisions and I wonder if, like them, he ended up being little more than a Norland nanny, anxiously telling a lit firework how to behave.

Not only did Kettler live just down the road from the Sussexes in Santa Barbara, but he also had the dream CV for the job.

He had spent nearly ten years in a crucial role at Patagonia, the outdoor recreational clothing company with a billion-dollar turnover and a mission to help save the planet, one fleece jacket at a time.

He met his wife Sarah there, and lovingly helped her to forage for herbs and plants when she launched her small batch shrub vinegar business, making 'sipping vinegars' flavoured with yuzu and plum to drink as aperitifs. Don't ask. It's California. They milk oats out there.

However, it is notable that Sarah shares many of the same values and motivations as her neighbour, Meghan. They could have been another dream team, bonding over fermented drinks and yoga. But it was not to be.

Three short months after he was hired as the man to guide Prince Harry through the next stage of his life, key aide Joshua Kettler is out

Three short months after he was hired as the man to guide Prince Harry through the next stage of his life, key aide Joshua Kettler is out

Prince Harry and Meghan hold the hands of two students as they are given a tour of Colegio La Giralda in Bogota yesterday

Prince Harry and Meghan hold the hands of two students as they are given a tour of Colegio La Giralda in Bogota yesterday

More recently, Kettler was Head of Strategic Partnerships at Cognixion, a 'mission-driven company' pioneering the use of AI to unlock speech for millions of people across the world affected by communication disabilities.

It is hard to think of anything more worthwhile or, frankly, wonderful. So here he is, this successful man of substance and drive, a seasoned public relations professional and true sportif who loves skiing and trail running.

He is also a steadfast supporter of conservation and the environment, a civic-minded good guy who would be an asset to any company. And if Joshua Kettler, with all his gravitas and experience and smarts, is not the perfect man for the job, then who the hell is?

Kettler's sudden exit, on the eve of the Sussexes' preposterous tour of Colombia, does suggest to me a volatile fracture of opinion.

Did he dare to say to Prince Harry, 'Come on, dude, be serious? I know you and Meghan want to focus on Archewell Foundation's promotion of safer digital environments in Colombia but, believe me, that is not the safety issue out there, unless you mean the popular practice of killing enemies by dropping grenades on them from commercially available drones.

'Guerilla groups, drug cartels, paramilitary organisations and the government are all fighting with each other like rats in a sack while the former guerilla, President Gustavo Petro, has recently been described as a 'performative militant' by New Yorker magazine.

'No, it is not exactly the Duke and Duchess of Windsor touring Germany in 1937 and taking tea with Hitler in Berchtesgaden but still, Your Highness, please consider the negative connotations of this deep fake state visit.'

And then he was promptly sacked for his disobliging opinion?

It's only a theory! Pure conjecture on my part because, of course, no one is talking. For every time another staff member leaves the employ of the Sussexes, a cloud of secrecy descends.

'They will all have NDAs up the wazoo,' as one American business expert told me, meaning that staff will have been asked to sign Non-Disclosure Agreements as a condition of their employment.

The Sussexes are great believers in liberty, freedom of speech and the eradication of misinformation, until it comes to those who work for them. Their ex-employees are pledged to secrecy until death – or else they can expect a knock on the door from Jenny Afia.

Yet you can't really blame Harry and Meghan.

We live in the time of the NDA which – in America at least – has become the definitive document of the age.

Recent estimates suggest that a third to a half of the American workforce has signed one.

Another theory: perhaps the constant churn of staff has more to do with the fragile nature of the Sussex business than the nature of the Sussexes themselves. For if you are keen on climbing up the career ladder, where is the structure here? What are the goals?

To consider the Archewell Foundation and the various scattergun projects the couple have been involved with recently is to lose sight of exactly what 'the mission' is these days.

Unless you conclude it is just a great big balloon of well-meaning hot air, with each new initiative launched in a blaze of publicity – only to fizzle out afterwards.

Earlier this month the royals-in-exile went on CBS Sunday Morning Show to announce The Parents Network, an online facility hosted by Archewell to support the parents of children who have died through online harm.

Some bereaved parents were duly drummed up and had to sit and listen to the Duchess tell CBS presenter Jane Pauley that she was once so miserable within the confines of the Royal Family that she 'just didn't want to be alive any more'.

Meghan also looked uncomfortable when Pauley called the Parents Network 'modest'.

However, this was a fair point and one echoed by tech commentator Mike Masnick, who asked on his popular Techdirt weblog if Harry and Meghan were simply burnishing their reputations by claiming to help others – without actually putting in the work.

'Prince Harry has a bit of a history of cosplaying as an expert on internet speech, without the actual expertise to back it up,' Masnick said.

'The Parents Network website provides precious few details – and seems to suggest the effort is really focused on just demonising social media.'

Meanwhile down in American Riviera Orchard, nothing much has happened since the Duchess of Success soft-launched her lifestyle brand in March this year.

There was some jam, a jar of homemade dog biscuits and then – nothing. A void that cannot be avoided, a great big lake of flake which has squandered any PR initiative gained by the launch.

Recently Meghan has been crazy busy filming the cooking and gardening show that will supposedly complement the hard launch of ARO in 2025, and the last we saw of Harry he was in Colombia posing for selfies in his crumpled linens and trying not to look miserable. Some public figures have a talent for kinship and generating affection wherever they go and some – what can I say? – do not.

Amid their ongoing staffing problems, Harry and Meghan are in perpetual danger of appearing like self-appointed experts on everything, a couple who are only out for themselves rather than their pet causes.

They are better than that, but their lack of loyal and long-serving aides to guide them, wise heads to advise them and staff to support them in their endeavours and difficulties only gets more obvious by the day.