Hari digs in to the history of the demonization of addicts in the United States. This started about a century ago as a federal police initiative, in the predecessor to the DEA.
One of the things the US did in the middle of the 20th century was to coerce other countries into agreeing to treaties criminalizing drugs -- the Paris Convention of 1931 https://en.wikipedia.org/wiki/Convention_for_Limiting_the_Ma... and the 1961 Single Convention. https://en.wikipedia.org/wiki/Single_Convention_on_Narcotic_...
If Hari's to be believed, the anti-addict stuff in the US was, at its core, racist. Cannabis was, he says, believed to cause violent insanity in black and brown people. The same was true of opium and similar drugs.
He doesn't make the argument that addiction is good, only that addicts are not evil or morally deficient. He does make the argument that prohibition causes addiction for several reasons:
(1) the iron law of prohibition: when a substance is prohibited, it drives out all but the most potent formulations of the substance from the market. Nobody smuggled lite beer during alcohol prohibition; they smuggled white lightning and 151-proof rum. The most potent formulations are most addictive.
(2) the various dealer effects.
a) Addicts to prohibited substances sell some to their friends to support their habits. This introduces more people to the substance. (This happened to me many years ago with cocaine. Fortunately for me I was broke at the time and my experience with the stuff seemed like dentist novocaine: boring).
b) Retail dealers cut the wholesale product with nasty adulterants to get more stuff to sell.
c) Dealer bigshots (guys with names like El Chapo) have an underworld kind of glamour to them.
d) Dealers outside the law have zero incentive to keep their products away from children.
(4) the lack of supervision of addicts getting their doses. Experiments in parts of England, Portugal, and Switzerland show that addicts who can safely get their doses in clinics lead productive lives and can, when ready, take on the task of curing their addictions.
It's counter-intuitive but true: decriminalizing drugs reduces addiction.
But, it will happen slowly. The narco-industrial complex is too powerful. Decriminalizing drugs means police layoffs. It means an end to most civil forfeiture property seizures, which will cut into government revenue. It eliminates a rich source of scare tactics for politicians. It takes a fat chunk out of gun and ammunition sales.
Just look at Massachusetts, where I live. Cannabis was decriminalized in November, and the law has been in effect for about a month. Police and politicians are wringing their hands about what to do.