There are two key problems with books that attempt to be objective about illegal drugs. The first is that for the most part their authors won’t admit to having used such substances for fear their own objectivity may be compromised. The second follows fairly logically from the first: who, precisely, are such books aimed at? If they are targeted at readers who already have a consuming interest in drugs (pun intended), then they are very likely – by definition – to know rather more about the subject than the author; and if they are for people who only have a tangential interest in the subject, why should they want to read about it at all? True, there may be such a thing as a “gateway” book about drugs that leads people deeper and deeper into compulsive reading about the subject, but I suspect neither of these titles will fulfil that role, no matter how vulnerable the reader is to literary addiction.

Antony Loewenstein never explicitly says that he hasn’t used drugs in Pills, Powder and Smoke, but nor does he ever indicate that he has. The personal information we gather about him is that he is something of an ingenue when it comes to the messy business of reportage in compromised and difficult environments. In the Philippines, where President Duterte’s government has conducted a “dirty war” against drug users and dealers for some years now (it’s claimed anything between 5,000 and 20,000 lives have been lost), Loewenstein sees the corpse of a man who has been gunned down by the police: “It was the first dead body I had ever seen, apart from that of a deceased relative. I felt fascinated and sickened, wondering if I was a vulture for taking so many photos.” No need to wonder, Antony, you were.

Why not visit Mexico? Or one of the major South American coca producers? Or Afghanistan?

Loewenstein is trying to give a grand survey of the contemporary, global “war on drugs”, but his choice of locations seems a little off kilter. The Philippines are certainly worth covering, as would be one of the major drugs trans-shipment locations for the South American cartels and European mafias that control the global trade. But Loewenstein goes to two: Honduras and Guinea-Bissau. Ditto, he visits and surveys three western countries’ drug policies – the US, Australia and Britain – despite opining that, really, the States has always been the sniffer dog wagging the other two nations’ tails when it comes to prohibition.

So why not visit Mexico, that Pandora’s box of a nation, out of which have come all the misfortunes of its northern neighbour? (At least according to American politicians.) Or one of the major South American coca producers, for that matter – or Afghanistan, the narco-state that has played the most significant role in providing western governments’ military-industrial complexes with their raison d’être?

Antony Loewenstein.

When it comes to the dirty wars waged by the US Drug Enforcement Agency, which, after 9/11, created a fictitious bogeyman called “narco-terrorism” to partner “Islamofascism” as a casus belli, Loewenstein gives a thorough and convincing picture of an utterly failed policy, driven by racism, neoimperialism and mere professional closure on the part of politicians and police. But right-thinking people knew the war on drugs was futile years ago, didn’t they? The very name gives the game away, for how can a war against an inanimate object ever be won?

For my part, I remember writing a feature on illegal drugs in Britain in the early 1990s, wherein I interviewed the then head of illegal drug interdiction for the NCIS (National Criminal Intelligence Service), who candidly admitted it was a waste of time and money trying to stop the flow of illegal drugs into the UK. Nowadays, it’s the Association of Chief Police Officers that is infinitely more radical than the political class – for its members see the dire consequences of criminalising drug users every day, in the form of ever more violent subcultures.

In Britain, Loewenstein hangs out with sex workers in Newcastle, a homeless man next to King’s Cross station and interviews a trio of the usual reformist suspects: Dr David Nutt, the government drugs tsar who was sacked for saying taking ecstasy was less dangerous than riding a horse; Amanda “hole in the head” Fielding, who runs the Beckley Foundation for research into psychedelic drugs; and the head of Imperial College’s new centre for psychedelic research, Dr Robin Carhart-Harris.

Just as in his reporting on the drug wars where he takes his lead from the likes of writers Roberto Saviano, whose Zero Zero Zero exhaustively chronicles who kills whom, and Jeremy Harding, whose superb Border Vigils correctly sites prohibitionism in the suite of anti-migrant measures adopted by the west, so in his reporting on harm minimisation, and the possible benefits of using (at least some) drugs, Loewenstein follows Michael Pollan, whose How to Change Your Mind: The New Science of Psychedelics has the virtue of being written by an author who admits to turning on and tuning in – if not dropping out.

On page 304 of her exhaustive survey of psychoactive drugs, Suzi Gage writes: “I would not encourage anyone to take any of the substances mentioned here.” Which, following what I’ve written already, invites the question: who is this book aimed at? True, Gage deals with legal as well as illegal drugs and for the most part – saving her rather coy little autobiographical asides – this is a competent survey. But people who take drugs tend to know a lot about them – that’s what a drug culture is: a vector carrying information not usually, by definition, disseminated in the media. I reached page 50 of Say Why to Drugs before I learned anything new – and this was only that the somniferous herb valerian is not in any way related to the addictive benzodiazepine, Valium.

Dr Suzi Gage.

Elsewhere, Gage – was she driven by nominative determinism to take up her calling as a drugs specialist? (gage being American slang for marijuana) – is less impressive, not seeming to be aware that cocaine is soluble (for injecting purposes) in water or that cannabis is a psychedelic. In common with many drugs specialists, she wants the latter to be in a class of its own, but this reflects its ubiquity rather than its pharmacology.

Also, as with most who attempt a scientific analysis of the effect of psychoactive drugs on mental and physical health, Gage has frequent recourse to the observation that statistical regularities in trials may reflect the prior dispositions of users – for psychosis, depression or whatever – rather than being caused by the drugs they ingest. To her credit, she adopts Timothy Leary’s rubric of “set and setting” – without crediting him – for understanding the panoply of different effects the same substance can have on different people, in different environments, but she is unable to follow this idea through to its logical conclusion, which is that intoxicants can only be understood at all in the real world, not the laboratory.

Really, this is the same as Loewenstein’s problem. At the end of his lengthy – and from my point of view, largely pointless – excursus, he contends: “As with climate change, small incremental shifts won’t ultimately suffice to address the drug war.” But really, healthy changes in the social use of intoxicants are always about small incremental shifts – it’s only addiction that courses through the body politic in great waves.

Will Self’s memoir of his drug-addicted youth, Will, is published by Viking.

• Pills, Powder and Smoke: Inside the Bloody War on Drugs by Antony Loewenstein is published by Scribe (£16.99). To order a copy go to guardianbookshop.com. Free UK p&p over £15

• Say Why to Drugs by Dr Suzi Gage is published by Hodder & Stoughton (£16.99). To order a copy go to guardianbookshop.com. Free UK p&p over £15