As the movement towards legalization gains steam, international drug control treaties are a big elephant in the room. To date, legalization advocates and politicians alike have focused on laws at the local and national level. Little attention, however, has been paid to the multilateral treaties that arguably conflict with those laws. Most efforts to push a federal solution to the disparate local/national treatment of cannabis ignore the United States’ treaty obligations. This conflict must be addressed to ensure a smooth path forward.

The international treaties are firmly anti-cannabis legalization. The 1961 United Nations Single Convention on Narcotic Drugs, which the U.S. signed and pushed through, classifies cannabis as a Schedule I and Schedule IV substance and requires parties to adopt “special measures of control…having regard to the dangerous properties” of marijuana and to “prevent the misuse of, and illicit traffic in, the leaves of the cannabis plant.” Additionally, the 1988 Convention Against Illicit Traffic in Narcotic Drugs and Psychotropic Substances requires states to criminalize almost all forms of marijuana activity and to “ensure that any discretionary legal powers under their domestic law relating to the prosecution [of covered offenses] are exercised to maximize the effectiveness of law enforcement measures in respect of those offences and with due regard to the need to deter the commission of such offenses.” Interpreting these treaties, the UN has stated that “the legalization of non-medical use of cannabis contravenes the international drug control treaties.”

Given the apparent conflict between the treaty requirements and legalization, commentators have suggested that the United States must renegotiate these instruments if it is to legalize and remain compliant with its international obligations. For example, in a 2014 article, Wells Bennet and John Walsh of the Brookings Institution argued that “[t]o avoid a damaging collision between international law and changing domestic and international consensus on marijuana policy, the United States should seriously consider narrowly crafted treaty changes. It and other drug treaty partners should begin now to discuss options for substantive alterations that create space within international law for conditional legalization….”

While this recommendation has not been implemented, an international movement in support of amending the treaties now appears to be developing. In January 2019, the Director General of the World Health Organization submitted to the Secretary General of the United Nations a recommendation that cannabis and cannabis resin be deleted from Schedule IV (though not Schedule I) of the 1961 Convention. Additionally, the Chief Executives Board of the United Nations issued a statement of commitment to “promote alternatives to conviction and punishment in appropriate cases, including the decriminalization of drug possession for personal use and to promote the principle of proportionality, to address prison overcrowding….” Nevertheless, amending three international treaties will not be easy and may take much longer than Congress is willing to wait to change federal law.

For those seeking legalization, the Strengthening the Tenth Amendment Through Entrusting States (STATES) Act, which was re-introduced by Senators Warren and Gardner on April 4, may provide a solution. There are at least three reasons for this.

First, the STATES Act would leave cannabis in Schedule I, while prohibiting federal law enforcement from prosecuting individuals and entities in compliance with state law and a new set of federal guidelines. Thus, it would arguably keep the United States in compliance with its obligations to criminalize cannabis.

Second, as noted above, the treaties require states (in the words of the 1988 Convention) to exercise their “discretionary legal powers … to maximize the effectiveness of law enforcement measures in respect of [covered] offences.” As the UN CEB noted in its January statement, “the conventions allow for sufficient flexibility for countries to design and implement national drug policies according to their priorities and needs….” Shifting enforcement resources from state compliant behavior to cannabis trafficking that involves sales to children, organized crime and diversion to prohibition states would allow the government to combat more effectively the kind of aggravated drug trafficking that the treaties were designed to eradicate. Such a legislative change is therefore, arguably, precisely the kind of discretionary decision that the treaties require states parties to make.

Third, the treaties also provide some flexibility to states based on their constitutional structures and make repeated reference to national constitutional limitations. For example, Article 36 of the 1961 Convention, which contains the main provisions on criminalization, begins with the words “Subject to its constitutional limitations, each Party shall…” Given that the STATES Act is based explicitly on the U.S. Constitutional structure and the balance that it attempts to strike between federal and state power, it is arguably consistent with the treaties’ deference to national constitutional structures.

Whether legalization is desirable from a policy perspective is a subject for another day. But if the federal government decides to move in this direction, it will have to reconcile the change in the law with the United States’ international treaty obligations. The STATES Act may be one way to square this circle.


Tom Firestone is located in Baker McKenzie's Washington D.C. office and Co-chair of the firm's North American Government Enforcement practice.