The United States enacted the Controlled Substances Act in 1970, which brought into the United States Code our obligations under as a signatory to the Single Convention on Narcotic Drugs. This treaty binds the United States against being able to enact meaningful reform of our drug laws and enforcement policies.
Reforming our drug laws and their enforcement, including removing threat of Federal prosecution over recreational marijuana users in several States, requires first withdrawing from that convention. Article 46 of the convention provides the ability to denounce the treaty, thereby ending its obligations on the United States. From there, meaningful reform of our drug laws becomes possible.