This year 2025 marks a significant and somber milestone: 100 years since the beginning of international cannabis prohibition. This is not a moment for celebration, but rather a crucial opportunity to reflect on the events that led us here, and what we must do to move forward.
Prohibition law in all countries around the world, are based on this international treaty control. In 2025, we have stopped counting the countries that initiated efforts to legalize… and then suspended or watered them down because of the treaty supposedly refraining them from legalizing. So, what are these old treaties? where do they come from? and why is it worth marking the date for this Centenary?
The Genesis of Prohibition: 1925 and Two Conflicting Treaties
The year 1925 was indeed a turning point, when cannabis was first brought under international control with the Geneva Opium Convention (adopted 19 February 1925), driven by the governments of Egypt and South Africa. Yes… cannabis prohibition was not initiated by the U.S., but by postcolonial African countries!
This international treaty included “Indian hemp” as a controlled substance, alongside opium, setting the stage for a century of its prohibition. However, it is essential to understand that this decision was not rooted in scientific evidence, but in classist, racist, and prejudices inherited from the colonial era that associated cannabis with the poor and marginalised communities.
The goal is to challenge authority, challenge the status quo and demand a more just world.
Interestingly, in the very same year, the Brussels Pharmacopoeia Treaty acknowledged cannabis’s medicinal applications by including it in the International Pharmacopoeia. This inclusion came after an overwhelming majority of countries had cannabis in their national pharmacopoeia, some for a long time (in Europe, Spain is the first country to include cannabis seeds in its pharmacopoeia in the late 1700s, Belgium includes cannabis herb as early as 1823, and Romania is the first country to add cannabis extract in its pharmacopoeia in 1863). This recognition of medicinal cannabis was temporary, however, as the plant was removed from the International Pharmacopoeia shortly after the Second World War.
A Biased Assessment
Ten years after the placement of cannabis under international control, in 1935, an international scientific review of 5 cannabis-containing medications (sold worldwide by the largest pharmaceutical company of the time, Parke-Davis) was conducted. It concluded that the plant was essentially harmless; these 5 medical preparations were harmful, but because of other ingredients like strychnine —not because of the presence of cannabis.
Unfortunately, the conclusions were shared just before the start of the Second World War. After the war, the 1935 scientific review was utilized by political actors for anti-cannabis misinformation, conflating the harmfulness of these Parke-Davis’ cannabis medicines with that of cannabis. And it wasn’t until 2018 that a new impartial scientific evaluation took place at the international level, recognizing newly the medical usefulness of cannabis and its limited and easily manageable adverse effects.
Wartime with Cannabis
Throughout the millennia of Homo sapiens–Cannabis sativa relationship, it is hard not to notice the particular relationship between soldiers and the plant, at all times and on all continents. The Second World War was no exception to this intimate relationship.
During the Second World War, there was a temporary surge in the cultivation of cannabis as hemp was desperately needed for military supplies by countries on both sides of the battlefront, including the UK and the USA, or Japan and Germany. This was the early stage of what would become a profoundly-established contradiction of the prohibition era: the acceptance of the industrial uses of cannabis for productivist purposes parallel to a criminalisation of health, wellness, leisure, pleasure, and spiritual uses of the same plant.
The Cannabis Embassy builds on activities begun in 1998 at the United Nations.
Interestingly, we often forget that prohibition was not an universally accepted concept at all times. In 1940 Mexico took a different approach, by legalising cannabis and all other drugs and prioritising public health, with the creation of addiction services, harm reduction, and legal supply of controlled drugs. Although this legalization was short-lived, with the US government pressuring Mexico to reverse its policy, this episode remains until today one of the rarest examples of sensible policy making, science-based drug policy, and nationwide normalisation of “mariguana” in the modern era.
The Devastating Human Cost
The global war on drugs has had a devastating impact on individuals and communities. Millions of anonymous victims of the chancy political experimentation that has been cannabis prohibition is perhaps best incarnated by the face of Phyllis Joyce Stalnaker Harris, a normal, humble person who was imprisoned for simple cannabis possession in the 1950s and labelled “weedhead” on her mugshot.
She is but one example of the many lives that have been ruined by these policies, which have systematically targeted the most vulnerable members of society —and even sometimes used drug policy and prohibition on purpose to target certain minority groups, as recognised by the advisors of former U.S. president Richard Nixon.
Control of Seeds
A lesser-known part of this Centenary of cannabis control is the evolution of plant control, which goes beyond cannabis but also affected its prohibition directly.
Following the Second World War, there was a push in Europe to develop new, low-THC cannabis varieties that had never really existed before. Facilitated by the UPOV treaty, which created a sort of patent system for new varieties of plants, this led to the replacement of traditional cannabis varieties with commercially driven ones, particularly relevant in Europe as registered varieties became the only allowed crops for “industrial” cannabis, leading to the progressive disappearance and total eradication of European cannabis landraces.
Prohibition has not always been a universally accepted concept everywhere.
The introduction of these stable low-THC cannabis plants also permitted, for the first time, to model nature according to anthropogenic concepts, namely, the artificial binary distinction between sativa and indica. This binary split of the cannabis genus between the “good” sativa and the narcotic “indica” from the Indies had been invented in the 18th century by French naturalist Lamarck from the bottom of his office, without ever travelling abroad to see any foreign cannabis plants. Only years after he proposed the idea, Lamarck was proven wrong, as he would be time and again by 19th century botanists from numerous countries, who showed that the climatic and cultivation parameters were the only responsible factors for the yield and strength of the resin, and not a supposed “species.”
Yet, after UPOV and the invention of low-THC plants, it is as if humans had managed to bend nature in order for it to fit the hypothesis of old Lamarck. And in doing so, sustaining prohibition and deepening its profound contradiction…
The Power of Activism and the Cannabis Embassy
Activism has been instrumental in shifting perceptions and policies surrounding cannabis. Grassroots movements, medical cannabis advocacy groups, and the Cannabis Embassy have challenged the status quo, raising awareness and changing public opinion.
The Cannabis Embassy, established in March 2024, is built upon activism that started in 1998 at the United Nations, at the moment when global leaders, motivated by the change of millennium, pledged to eradicate the plant within ten years. The plant was well equipped to defend herself, and survived these ten brutal years. But people are not as resilient as the plant. As the eradication-mania continued on different frequencies since 2008, advocates and activists have gathered to be a voice for cannabis communities worldwide and a protector of their rights, eventually crystallising in the Cannabis Embassy, last year.
As we consider the next 100 years, we must ensure that the benefits of legalisation are distributed equitably. We need to move beyond simply legalising cannabis for adult or medicinal use, and not only take into account its industrial applications, cultural significance, and potential role in sustainable agriculture, but importantly discuss the “how” to legalise, and discuss it with us. Policies must support small businesses, encourage environmental sustainability, prioritize social and restorative justice, legalization must recognize the forms of organization born under prohibition that are beneficial for society —like home growing and cannabis social clubs— and engage in proactive efforts to reconnect with all traditional cannabis communities in urban and rural setting worldwide, in an approach of mutual respect, consultation, consent, fair repartition of benefits and meaningful taxation schemes. Legalization must fight stigma and recognize the beauty of cannabis heritages and cultures.
A Paradigm Shift: Reclaiming the Relationship
This is about challenging authority, questioning the status quo, and demanding a more just world. The way we treat cannabis reflects our attitudes toward conviviality, individual freedom, social justice, scientific evidence, and relationship with nature.
There are countless countries in the world today that have decided to start the legal process leading to the legalisation of cannabis.
As we mark this “Centenary of Cannabis Prohibition–Global Cannabis History year”, we must choose a path that is rooted in knowledge, compassion, and respect for the plant and its potential for healing, creativity, and connection. The international drug control established by the 1925 Geneva Opium Convention remains in effect 100 years later, and a more coordinated effort by civil society is needed to overcome the devastations brought by this treaty control. It is time to reclaim our relationship with cannabis, freeing it from the constraints of stigma and prohibition.
This is not just about cannabis; it is about our values. It is about progress, not perfection; and it is about the future we want to create, both individually and collectively.
Join the world during the year 2025 in commemorating the Centenary of Cannabis Prohibition–Global Cannabis History Year, and help building the next 100 years of peace on cannabis.
Authors: Kenzi Riboulet-Zemouli & Myrtle Clarke (Cannabis Embassy)
