Why Cannabis Was Criminalised and Alcohol Wasn't

The legal status of cannabis and alcohol in the modern world is not a product of scientific evidence, public health reasoning, or rational policy-making. It is the result of a specific set of historical forces — racism, corporate competition, political opportunism, and bureaucratic empire-building — that converged in the early twentieth century to produce a regulatory regime that persists, largely unchanged, to this day.

Before Prohibition

Cannabis has been used for medicinal, recreational, and industrial purposes for thousands of years. Hemp — the non-psychoactive variety of the cannabis plant — was a major agricultural crop throughout the nineteenth century, used for rope, textiles, paper, and building materials. Tinctures of cannabis were widely available in pharmacies across Europe and North America, prescribed for pain, nausea, insomnia, and a range of other conditions by mainstream physicians.

In the United States, cannabis was listed in the United States Pharmacopeia from 1850 until 1942. Queen Victoria's personal physician, Sir J. Russell Reynolds, prescribed cannabis for her menstrual pain and described it as a “foremost” medicine ( [Reynolds, 1890, The Lancet]). There was no moral panic about cannabis, no public health crisis attributed to it, and no serious movement to ban it.

The Failure of Alcohol Prohibition

Alcohol, by contrast, was the subject of intense political and social conflict. The temperance movement, driven largely by Protestant religious groups, had been growing since the early nineteenth century. The 18th Amendment to the US Constitution, ratified in 1919, prohibited the manufacture, sale, and transportation of alcoholic beverages nationwide. The result was not a sober utopia but a catastrophic failure: bootlegging, organised crime, corruption of law enforcement, and widespread consumption of dangerous illicit spirits. The 18th Amendment was repealed in 1933 by the 21st Amendment — the only constitutional amendment in US history to be repealed by another. The experiment had lasted just 14 years.

The Marihuana Tax Act of 1937

The Marihuana Tax Act of 1937 effectively criminalised cannabis at the federal level in the United States. This was not a public health measure. It was the product of a deliberate campaign of racist propaganda orchestrated by a small number of powerful individuals with clear financial motivations.

The public face of this campaign was Harry J. Anslinger, the first Commissioner of the Federal Bureau of Narcotics. Anslinger fanned public fear with lurid, fabricated stories of cannabis-induced violence and insanity, frequently invoking racial stereotypes about Mexican immigrants and African American jazz musicians ( [Marihuana Tax Act of 1937, Congressional Archives]). He explicitly stopped using the scientific term "cannabis" and adopted the Spanish slang "marijuana" to tie the drug directly to xenophobic fears of Mexican immigrants.

William Randolph Hearst, the newspaper magnate whose media empire reached an estimated 20 million readers, had a direct financial interest in the destruction of the hemp industry. Hearst owned vast tracts of timberland that supplied paper for his newspapers and had invested heavily in mechanical wood-pulp mills. Hemp was a superior raw material — it grows faster, yields more fibre per acre, and produces stronger paper. It posed an existential threat to Hearst's timber-based paper empire ( [Hearst Corporation, History Archive]). His newspapers ran a sustained campaign of sensationalised anti-cannabis propaganda.

The DuPont chemical company had a parallel motive. DuPont had recently patented nylon, a synthetic fibre competing directly with hemp in textiles and cordage. The company's leadership recognised that cheap, renewable hemp was a formidable competitor to its synthetic products ( [DuPont Archives]). The pharmaceutical industry also stood to benefit — as modern medicine shifted toward synthetic, patentable chemical pills, a raw botanical plant that any citizen could grow for free in their garden was entirely incompatible with their profit models.

The 1961 UN Single Convention

The globalisation of cannabis prohibition was cemented by the United Nations Single Convention on Narcotic Drugs of 1961. Heavily driven by US diplomatic pressure, this treaty classified cannabis alongside heroin in Schedule IV — the most restrictive category — and forced signatory nations to criminalise it domestically ( [UN Single Convention on Narcotic Drugs, 1961]). The World Health Organization's Expert Committee had concluded that cannabis had therapeutic potential and recommended reconsideration, but this was ignored due to political momentum.

The War on Drugs and the 1971 Escalation

In 1971, US President Richard Nixon declared the modern "War on Drugs." John Ehrlichman, his domestic policy adviser, later admitted: "The Nixon campaign had two enemies: the antiwar left and black people. We knew we couldn't make it illegal to be either, but by getting the public to associate the hippies with marijuana and blacks with heroin, and then criminalising both heavily, we could disrupt those communities" ( [Baum, 1994, Harper's Magazine]). The UK aligned with this geopolitical shift by passing the Misuse of Drugs Act 1971 — the same year — locking cannabis into Class B status and ignoring its medical history ( [Misuse of Drugs Act 1971]).

This convergence of interests — Anslinger's bureaucratic ambition, Hearst's paper monopoly, DuPont's synthetic fibres, the pharmaceutical industry's shift to patentable chemicals, and Nixon's political strategy — produced the global prohibition regime. The law was not passed because of evidence that cannabis was harmful. It was passed because powerful economic and political interests benefited from its prohibition.

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