Have you ever wondered what an advert for cocaine might look like if illegal drugs were legalised? I'm looking at one now. An attractive young woman in an extravagant feathered hat and a low-cut dress with a foaming lace collar, curls tumbling prettily down over her forehead, is holding a bell-shaped tea glass three-quarters full of a brown liquid. Her arm is sheathed in a white elbow-length glove and her pinkie is extended. The marketing slogan is displayed in an oval plaque next to a vase of yellow roses: "Drink Coca-Cola, 5¢."

Coke hasn't had cocaine in it for more than a century (the ad is from the 1890s), and the days are long gone when Sir Henry Wellcome, whose legacy endows the Wellcome Trust's bounteous donations to medical research, grew rich by flogging cocaine pills around Britain under the brand name Forced March.

But it's easy to imagine what it would be like a few years down the road if the arsenal of modern marketing was put, without restrictions, behind selling ecstasy or ketamine. In a report last year calling for a complete ban on alcohol advertising, the British Medical Association pointed out that the booze industry spends £800m a year promoting its products. Sure, Smirnoff competes with Absolut and Heineken competes with Carlsberg, but every penny of that £800m is pro-alcohol propaganda. For comparison, £540m is spent on all government advertising.

We're at an interesting moment in the eternal ethical struggle over our love of what Nietzsche sneeringly called poison – as in "a little poison now and then: that makes pleasant dreams. And much poison at last for a pleasant death."

The same sort of thoughtful, learned voices saying Britain's liberal attitude towards alcohol has gone too far are saying that our illiberal attitude towards other dangerous recreational drugs has gone too far in the other direction. The cynical assumption would be that any hope of a wise synthesis – tighten up on alcohol, loosen up on drugs – is doomed. But there are some interesting signs.

In his article on the catastrophe of drugs prohibition in the British Medical Journal – praised by, among others, the outgoing head of the Royal College of Physicians, Sir Ian Gilmore – Stephen Rolles attempts to jump ahead of the pro- and anti-legalisation parties by imagining what a post-legalisation world might look like.

He sets out five pragmatic, concrete ways drugs use could be legally controlled – by specialist pharmacists, by licensed retailers, by Dutch-style coffee shops "potentially also for smoking opium or poppy tea". None of his ideas would make it as easy to harm yourself with "drugs" as it is now to harm yourself with alcohol. It's a weekday noon as I write this, and if I wanted it, a fatal dose of vodka from the off-licence is three minutes' walk and £30 away.

A few days ago the coalition put out a call for ideas for its new drugs strategy, due at the end of the year. The consultation paper is tainted by "big society" flim-flammery and still encourages the idea that alcohol's special status vis-à-vis other dangerous drugs is something other than an arbitrary social construct. But with questions like "Which drugs (including alcohol) should prevention programmes focus on?" it does at least put booze in the same context as heroin, acid, cocaine and so on.

This could be a disaster, of course, if the hairy right arm of the coalition wrestled control of drugs policy from its delicate left limb and even tighter drugs laws were combined with a punitive war on teenage drinkers.

It's curious that the English-speaking country most intimately acquainted with the disastrous results of complete alcohol prohibition – the United States, which criminalised alcohol from 1920 to 1933 – has, despite legalising that particular drug, prosecuted its "war on drugs" – other drugs – with ever-increasing ferocity. The effect on supplier countries of American citizens' appetite for illegal substances is well known – the recent massacre of 72 people by a Mexican drugs cartel was only the latest horror wreaked indirectly by the war on drugs, which has killed 28,000 in Mexico since 2006. But the insane zeal of the war is hurting the US in all sorts of ways. America now has one in every 100 of its citizens in prison, five times more than Britain. A powerful piece of reporting in last month's Economist highlighted the case of a doctor who served four years in prison because patients sold on painkillers he had legally and justifiably prescribed to them.

I've never taken "hard" drugs. I've sometimes wondered whether my dinner guests were expecting me to serve cocaine at some point, but I've never been sure when to dish it up – before the cheese, or after? The food books are silent on the matter. I drink alcohol. Once in a while I get drunk. I love wine; I hate coming out of the cinema at 10.30 and seeing the bars getting ready to close. What makes me uneasy is the hypocrisy of a society which offers such extremes of punishment and encouragement towards two sets of variously pleasant and harmful substances, a society which on a plane will give you one mind-altering substance for free and arrest you if you try to ingest another.

The current transition tobacco seems to be making from the category of decent, respectable drug to indecent, disgraceful drug suggests alcohol could eventually make the same journey. I hope not. Turning alcohol into an outlaw would be as primitive an act of moral fetishisation as the outlawing of marijuana or, indeed, the putting of animals on trial in the law courts in medieval times. But that doesn't mean alcohol should have a special status that prevents its abuse being put in the same context as abuse of other drugs.

It also blinds us to the way that other countries' controls over alcohol use and abuse could be models not just for tightening up on booze here but for loosening up on drugs.

In Toronto last year, I had an encounter with the province of Ontario's government alcohol monopoly, the Liquor Control Board of Ontario. Having availed myself of the city's late-opening bars, I had no idea there was a government monopoly until I had to grab a last-minute bottle of wine to take to a friend's dinner. It took half an hour to find the nearest LCBO shop. A security guard was barring entry to a prosperous drunk; the queues were enormous; the choice limited. It was clean and bright, but there was an atmosphere of anxiety and desperation. As a model for tightening up on alcohol, it would take some getting used to. But as a model for loosening up on other drugs, it's a place to start thinking.