Cannabis prohibition under U.S. federal law is nonsensical and causes many problems, from oppressive taxation to civil rights violations. Under international law, however, things may be even worse. Fortunately, it was reported this week that the United Nations (U.N.) will finally take a closer look at cannabis prohibition this fall. It was also reported that the World Health Organization (W.H.O.), an agency of the U.N., has recommended that cannabidiol (CBD) no longer be controlled under international law. Both developments are terrific news.

For public international law nerds, like me, the question of why international law is more intractable than U.S. law on marijuana is fun stuff. The short answer is that cannabis, along with opium poppy and coca bush, is restricted not just through “scheduling”, but by the core text of the principal treaty at issue. This means that under international law, 185 or so countries are going to have to agree to amend the Single Convention on Narcotic Drugs of 1961 (“Single Convention”) (specifically, Articles 1, 22, 28 and 49) in order to truly end prohibition. Then, cannabis would also need to be removed from the Single Convention’s Schedules I and IV. All of that is no small feat.

Still, it isn’t impossible that the Single Convention would be amended to loosen or abolish restrictions on cannabis. The treaty was amended once before, by the 1972 Protocol, which inter alia amended Article 22 to require nations to actually enforce laws on their books against both poppy and cannabis cultivation. Since 1961, the U.N. has also taken other action on controlled substances, mainly through the Convention of Psychotropic Substances of 1971 (which will need amending one day, too) and the Convention against Illicit Traffic in Narcotic Drugs and Psychotropic Substances of 1988. So, the U.N. does re-think its stance on controlled substances from time to time, and for better or worse.

Like other international treaties that deal with drugs, the Single Convention is not self-executing. This means that signatory countries must pass domestic legislation to fulfill their treaty obligations. For its part, the U.S. passed the federal Controlled Substances Act (“CSA”) back in 1971. Unlike with the Single Convention, cannabis is not included anywhere in the body of this law. Instead, “marijuana” and other items are listed on separate “schedules” to the CSA. Each schedule then dictates the extent to which those items are controlled. “Marijuana” is a Schedule I drug with “no accepted medical use” and a “high potential for abuse.” That’s not so different than the Single Convention’s placement of “cannabis” at its Schedules I and IV, reserved for drugs that are “particularly liable to abuse and to produce ill effects” and where “such liability is not offset by substantial therapeutic advantages.” It’s important to note that even if the Single Convention were abolished entirely, its legacy would live on in the CSA and other domestic laws of its signatories, until those laws were also repealed.

Because the Single Convention has not been amended with respect to cannabis legality, it is controversial whether the U.S. has acted lawfully in allowing many of its states to promulgate medical and adult use marijuana programs in defiance of that treaty and the CSA. Recent U.S. delegations to UNGASS have made the argument that there is “sufficient flexibility” under the Single Convention to accommodate what has occurred under our federalist system of government. That’s a topic for another day, but suffice it to say that the “sufficient flexibility” argument is a thin one.

Many countries are no longer bothering with legal arguments, and simply ignoring their treaty obligations altogether. Canada and Uruguay are signatories to the Single Convention, and those countries have fully legalized sale and distribution of cannabis. Canada, for one, likely won’t even bother to withdraw from the Single Convention or submit reservations: It will just violate the treaty. Other countries around the world, from Israel to Germany to Columbia to Australia, have also pushed ahead to import or export medical marijuana in recent years; commercial legalization is a natural next step. Finally, countries like the Netherlands and Spain license or tolerate commercial or quasi-commercial marijuana activities.

Clearly, the Single Convention is outdated when it comes to cannabis prohibition, and global enforcement against licit marijuana economies is both impractical and legally problematic. In the coming months and years, countries will continue to legalize marijuana in abnegation of their treaty obligations, whether for moral or economic reasons. So let’s hope that the U.N. starts by acting on the W.H.O. recommendation to loosen controls on CBD, which shouldn’t be terribly difficult. But most importantly, let’s hope for an enlightened “big picture” approach on cannabis, even if that takes some work.