An open letter from PETA to International Olympic Committee (IOC) President Thomas Bach namechecked skateboarding, surfing and sport climbing as "sports that are of current interest" while observing that the Olympics had "evolved" to include them

The main point of the letter, which was signed by Kathy Guillermo, an official in PETA's Equine Matters Department, was to urge Bach to "eliminate all equestrian events" from the Games.

This was in the wake of three separate incidents in modern pentathlon and equestrian competitions at Tokyo 2020.

Modern pentathlon's grasp on a place on the Olympic sports programme has appeared precarious for some years now.

It has little profile outside the Games and was conceived as embodying - to quote David Miller’s Official History of the Olympic Games and the IOC - "the essential disciplines in the training of a military officer".

Not only has this become anachronistic - one-fifth of the way through the 21^st century, a grounding in esports and drone-craft would be a sight more useful than fencing for today’s young officers - but the whole link between the Olympics and notions of national defence withered away long ago.

When Baron Pierre de Coubertin initially plucked the Olympics from the pages of history, some of the thinking that planted the seed was linked to the desirability of better military preparedness.

This was in keeping with part of the justification for the original Games: in Ancient Greece, as in fin-de-siècle France, the development of a corpus of young men with the motivation, intellectual capacity and physical fortitude to make a good fist of defending their fatherland, if needs must, was held to be no bad thing.

The First World War, with its gruesome affirmation that, in the modern world, military success hinged far more on industrial than physical prowess, effectively put paid to such romantic ideas.

In this broad context, modern pentathlon can ill afford headlines such as "German pentathlon coach thrown out for punching horse" on the one occasion in every four years when the sport returns to the international spotlight.

When it first appeared on the Olympic programme, at Stockholm in 1912, the modern pentathlon competition stretched over no fewer than six days, including two entire days of épée fencing.

In recent times, it has seemed to me increasingly that the main thing stopping it from being dropped altogether, along with the political clout of some of its supporters, is its status as a brainchild of de Coubertin himself.

In the age of "change or be changed", one wonders for how much longer that pedigree can protect it.

For equestrian sports, by contrast, PETA is, I think, a long, long way from seeing its wishes fulfilled.

For one thing, the international governing body has, in Ingmar De Vos, a smart, hard-working leader, with guts and sensible priorities, who is increasingly well-respected in Olympic circles.

Just as importantly, while accidents are inevitable and horses make poor patients, horse sport's attitude to animal welfare has "evolved" enormously and creditably over recent decades.

I spent part of the weekend engrossed in the Official Report on the cross-country elements of the three-day event at the Berlin 1936 Olympics.

It is clear from this that the organisers' prime aim was to provide an extraordinarily challenging test for horse and rider.

The cross-country competition was actually in five phases, covering 36 kilometres, with 47 obstacles; it was designed to take around two hours to complete all told.

One obstacle - the pond - was so difficult that, of 46 competitors who attempted it, 18 horses fell and a further 10 "unhorsed their riders without falling themselves".

This was even though many riders had previously "studied the pond with special care, removing their clothes and attempting to find the best route through the water".

No fewer than three horses sustained life-ending injuries in that 1936 competition.

Hungary’s Legeny "suffered an inexplicable splintered fracture of the fetlock… when he stumbled on perfectly even ground"; Sweden’s Monaster "tore the tendons of both front legs and had to be killed"; and Slippery Slim from the United States fell at the pond and "was lying in such an unfortunate position that in his efforts to rise to his feet he broke the upper part of his forearm and dislocated his knee - incurable injuries".

To repeat: accidents will continue to happen; but such a toll - and such a course - would thankfully be completely unacceptable today.

For at least 30 years now, the main function of the Olympics, beside entertainment, has been to raise money for international sport and the multitudinous bureaucracies it has spawned.

Given the imperative of attracting maximum attention for the brands and other commercial interests which put up most of the money, and given the new audience-measurement and -monitoring tools that digital media makes possible, it is each discipline’s pulling power that, one suspects, more than anything will determine its Olympic future in years to come.

This will be as true for the new kids on the block, ie surfing and sport climbing, as for equestrian events and the modern pentathlon.

It is part of the legacy of coronavirus that changes to the Summer Olympic sports programme look set to be relatively few between Tokyo 2020 and Paris 2024.

I would be very surprised if such changes are not considerably more extensive between Paris 2024 and Los Angeles 2028.