If you’ve ever wanted to own a pet that’s the size of a man, specifically bred for violence, and associated with at least eleven fatal attacks on humans in the UK since 2021, you may now be out of luck.

The American bully XL — essentially a new type of inbred pit bull — weighs up to 75 kilogrammes, and it is thought to be behind a frightening rise in maulings of children, adults and other pets. One woman, who bravely fought off an American bully that attacked her dog, attributes her own pet’s survival to the fact that the bully was “getting tired” after having already caused injury to three other dogs and three people.

Breed-specific legislation has been very effective at minimising risks

Since it is a new type of dog, the American bully is not covered by the Dangerous Dogs Act 1991 — which makes it illegal to breed, sell or exchange dogs of a small number of especially aggressive breeds, or to allow them out in public except muzzled and on a lead. Since a video showing an American bully chasing down and attacking people on a busy street in Birmingham caught the attention of home secretary Suella Braverman last weekend, it looks likely that the bully will soon be added to the prohibited list.

Opponents of a ban — which, perhaps surprisingly given the number of pet deaths attributable to American bullies in recent months, include the RSPCA and the Dogs Trust — make a number of arguments. Firstly, there’s denial that any one breed is more predisposed to violence than any other: either pointing out that “all dogs can bite”, or arguing that “it’s the owner, not the breed”. Next, there’s the suggestion that “breed-specific legislation” won’t work anyway, because people will ignore it, or because various technicalities will supposedly make it difficult to enforce.

This is nonsense: breed-specific legislation has been very effective at minimising risks to the public from dogs over the three decades it has been in place. Pit bulls are one of the prohibited breeds in the UK; in the USA, where they are generally not subject to restriction, fatal dog attacks per capita are twice as high, with attacks by pit bulls more than making up the difference.

We see this argument again and again in all sorts of contexts. “If you ban this thing that I don’t want banned, that won’t stop it from happening!” For the right, it’s gun ownership; for the left, it’s abortion (“you can’t ban abortion, you can only ban safe abortion”), prostitution and drugs. Then of course there’s the view that it’s literally impossible to prevent children from watching pornography, which seems to forget that children generally first stumble across online porn by accident, rather than seeking it out. No, most tweens are not tech-savvy enough to get around age restrictions even if they want to.

It’s true that totally eradicating a certain behaviour may well be impossible. This doesn’t mean that prohibiting it is ineffective. Granted, if someone really wants to do something, they will probably find a way — but most people aren’t hell-bent on doing things. If you make something more difficult, more risky and more socially censured, fewer people will do it.

A side effect might be a rise in dangerous practices from the subgroup who are hell-bent on doing the thing you’ve prohibited, be it backstreet abortions or drug smuggling. The human cost of that increase is something that must be weighed up when considering a ban. Let’s not pretend that the overall rate of the prohibited behaviour won’t go down, though, potentially by an awful lot — or on the other hand that decriminalising a behaviour, making it destigmatised and easily available, won’t make it more common.

American gun control proponents are fond of pointing out that the UK and Australia both tightened firearms restrictions in the wake of mass shootings in the 1990s — and neither has seen gun violence on anywhere near the same scale since then. If our politicians had believed that “you can’t ban guns, only responsible gun ownership”, how many more Dunblanes might we have had in the intervening years?

Or take sex work. Reliable figures for the number of women in prostitution or the number of buyers are hard to come by. We can however compare Germany, which in 2002 decriminalised all aspects of the sex trade, including pimping and brothel keeping, to nearby Sweden, which introduced the “Nordic model” (criminalising sex buyers) at around the same time in 1999.

If a Swedish man pays for sex, he has to want to do it a lot more

In German cities, “drive-thru brothels” and multi-storey “mega-brothels” offering special deals, like discounts on a burger, beer and sex, can be openly advertised. Some local authorities have installed portaloo-style eco-toilets intended to also function as “sex boxes”, with a specially added second door to make it harder for women to be trapped in them by punters, because residents are “sick of all the [paid] sex going on in staircases and bushes”.

Meanwhile in Sweden, police officers go out at night and arrest men who are paying for sex. One officer is quoted as saying, “My job is to arrest as many men buying sex as possible and so far I think I have arrested around 700 … they are taking a huge risk.”

If a Swedish man pays for sex, he has to want to do it a lot more than a German man does. One report states, “It is not uncommon for German men to celebrate stag nights in brothels or for football clubs to visit them after a game.” German brothels are filled mainly with women from poorer countries in Eastern Europe — some there by choice, others not — and this makes logical sense. If you were one of the sex traffickers targeting Ukrainian refugees, bringing your victims to Berlin would make a lot more sense than bringing them to Stockholm.

The argument that bans don’t work is a dishonest one. Part of the case against abortion bans, for instance, is that they result in raped middle-schoolers becoming mothers precisely because they do prevent abortion. You don’t tend to see people arguing the other way around — that they wish it were possible to prevent some behaviour they strongly disapprove of, but since sadly it isn’t, we’ll just have to accept it. When activists claim that a ban they oppose won’t be effective, generally the reason is not that they think it won’t work: it’s because they are afraid it will.