Implications of adult-use legalisation for compliance with international law

The central basis for international control of the movement of cannabis around the globe is the 1961 UN Single Convention on Narcotics (the “Single Convention”), which is enforced by the International Narcotics Control Board (the “INCB”). The key provisions are as follows:

Regarding Article 36, ‘possession’ in this context has generally been considered to mean ‘possession and use for the purposes of trade’, which has allowed countries to reduce the level of criminalisation attached to the possession of cannabis for personal use.

It would seem to be clear, however, that the legalisation of adult-use cannabis falls foul of Article 4, and it is indeed the case that countries that have proceeded to legalise do so knowing that the INCB does not consider their justifications to be legitimate. For example, the Netherlands and Switzerland hold that their adult-use legalisation is within the Single Convention, classing it as for medical and scientific purposes, namely “pilot trials” giving them valuable data on the health and wellbeing of their citizens, whereas Canada goes the opposite way and openly accept that they are in breach. In the United States, they seek a workaround by holding that the Single Convention only applies at a federal level where adult-use cannabis is still prohibited.

Thus, whilst it appears that signatories are willing to ‘fudge’, or indeed ignore, Article 4 somewhat as regards internal legalization and trade of adult-use cannabis, where they are as yet unwilling to contravene is regarding importing or exporting such material across international borders for recreational purposes. Save for a signatory withdrawing from the Single Convention and re-joining with a caveat on this prohibition, or jurisdictions coming together to force a new interpretation under Article 41 of the Vienna Convention on the Law of Treaties, to have cannabis removed from the list of prohibited narcotics.

For Ireland this could be interpreted as Decriminalization at the Federal level, to enable Medical use and scientific study, without full legalization for international trade. While the Oireachtas could enable legislation that would structure the rules around production and consumption of cannabis to be handled at the county level and in doing so, such as with a process similar to the citizens assemblies and still be in compliance with the UN Single Convention.
This would also enable residents to be able to have a larger role in the rules governing their area, which means that some counties may choose to continue to ban cannabis. Overall that increases political engagement of the general populace.

Alternatively, Ireland could go the same route as California and the Oireachtas could label all production and consumption as Medical while giving health providers the power to prescribe cannabis as they see fit, which would not violate Article 4.

Or there is the Canada option, with Legalization on the federal level and a willingness to challenge the UN definition of Cannabis as a dangerous narcotic, though that has not happened to any country as of yet, while there are technically 40 countries which would currently be in breach of article 36, half of which are in Europe.

Whatever the case, the global cannabis market is estimated to be worth, in terms of sales, somewhere around US$44.2 billion today, and is estimated to break US$100 billion by 2026.

In simple terms the following distinctions should be noted:
 Decriminalisation refers to the removal of criminal status from a certain behaviour or action. This does not mean that the behaviour is legal, as drugs can be confiscated and non-criminal penalties may still be applied. In the drug debate, this term is usually used to describe laws related to personal possession or use rather than drug supply. Examples of countries which
have decriminalised drug use or personal possession might include Luxembourg (only cannabis), Croatia, Portugal and Slovenia.


 Depenalisation refers to the introduction of the possibility or policy of closing a criminal case without imposing punishment, for example because the case is considered ‘minor’ or prosecution of it is ‘not in the public interest’. Examples may include Austria, Germany and Poland.

 Legalisation refers to making an act lawful that was previously prohibited. In the context of the drug debate, this usually refers to removing all criminal and non-criminal sanctions, although regulations may limit the extent of the permission, as is the case for alcohol and tobacco. Penalties for breaching these regulations may be criminal or non-criminal. This term is generally used in the context of drug supply. Examples might include the systems in Uruguay and the US states of Alaska,
Colorado, Oregon and Washington;
in Europe, the Dutch system of cannabis sale through coffeeshops is only the toleration of an unlawful act.