Cannabis may or may not be a gateway drug, but the debate over legalising its medical use is certainly a gateway debate.  Were this not so, the tale of Billy Caldwell, the boy who fell seriously ill after his medical cannabis was confiscated at Heathrow, would have gained far less media projection.  On this site recently, Blair Gibbs suggested that legalising cannabis for medical use could lead to it being legalised for recreational use.  Previously, Steve Moore recommended that it should be.

This morning, William Hague weighs in, making much the same argument in his Daily Telegraph column – that’s to say, for a “lawful, regulated market” in the drug.  In doing so, the former Party leader is blazing a trail: he knows perfectly well that the Prime Minister, lacking a majority for infinitely less contentious proposals, couldn’t even begin to think about legalisation without a manifesto commitment, in the unlikely event of her being willing to do so in the first place.

But just as the debate over the legalising cannabis for medical use is a gateway one, so the dispute over legalising it for recreational use is one, too.  Admittedly, its legalisation for such use in some American state has been quarantined from the legalisation or decriminalisation of harder drugs.  But discussion about both cannot ultimately be separated from the disputes about cannabis.  The arguments that Hague makes about cannabis can be transposed to other illegal substances: that it is easily available; that it is stronger than it was, with grave consequences for public health; that the law is not always enforced; that prohibition is expensive; that “the only beneficiaries are organised crime gangs”.

In any event, the gateway argument about cannabis use leading to harder drug use, plus the certainty that legalising it for recreational use would have knock-on effects, whatever those might be, on the remaining illegal drugs market means that the debate necessarily widens.  Nor can considering this illegal market be separated from thinking about about the legal one.  Like people in other advanced countries, Britons are huge users of legal drugs.  The pharmaceutical industy is one of the country’s commercial success stories.  Then there is the question of legal highs, in which inventive producers and consumers keep, very often, one step ahead of the law.

The debate in one sense leads nowhere.  This Government will not legalise cannabis for recreational use.  End of discussion.  Nor can the broad sweep of present policy be shown to be failing if consumption is the test: overall, illegal use has declined over the past ten years.  But the matter cannot be brushed aside quite so easily.  Easier availability of more illegal drugs over the past 50 years or so has affected public attitudes.  Opinion polls tell us many things, but many show support for less restrictive approaches, though whether these might be legalisation or decriminalisation or a mix of both is unclear.  Politicians are doing exactly what, at least in this case, cynics would expect them to do – following, not leading: waiting, perhaps, for public opinion to reach a clear tipping-point, at least on cannabis.

We make one additional point.  Any eventual review of drugs policy as a whole must focus on collective consequences rather than individual rights.  Potential reform has implications for children, including unborn ones, for parents, and for the places that might host drugs tourism in the event of changes to the law.  It would also have consequences for taxpayers: whether savings on police and security costs would be outstripped by new healthcare costs, physical and mental, is a subject of fierce debate.  As John Donne almost put it, no pothead is an island.

In the event of the great national debate that we’re not having, public opinion might just swing behind a Swedish approach rather than a Portugese one – that’s to say, towards zero tolerance.  But this is not the trend internationally.  It is surely significant that the legal bars on cannabis are being breached in the very country whose puritan inheritance has driven the worldwide “war on drugs” – namely, America.

At any rate, Hague won’t have forgotten from his own brush with cannabis – in political terms, that is.  When he was Conservative leader, Ann Widdecombe, then Shadow Home Secretary, backed raising fines for possession; inevitably, journalists swooped on Shadow Cabinet members; five of them then admitted to having smoked it in their younger days.  We quote from a contemporary account: “Letwin said he had tried the drug only by accident while at Cambridge University, because friends mixed some cannabis in with his pipe tobacco.”