The bedrock of the global drug control regime is the Single Convention, so called because it largely replaced the previous international agreements that had been developing piecemeal since the early years of the twentieth century.  The prohibitionist character of the Convention is beyond doubt.  Signatory nations are obliged to limit exclusively to medical and scientific purposes the production, manufacture, export, import, distribution of, trade in, use and possession of drugs.  The Convention pays particular attention to plant based drugs such as opium, heroin, coca, cocaine and cannabis. It places more than one hundred illicit substances in four schedules, that is to say lists of drugs or preparations that are under the Control of the Convention, with drugs being grouped according to their perceived dependence creating properties.

Constructed as a companion instrument to the Single Convention on Narcotic Drugs, the 1971 Convention came about as a result of a growing global concern for the harmful effects of psychotropic substances, including synthetic drugs such as amphetamines, barbiturates and LSD.  In a similar fashion to that of the 1961 Convention, psychotropic substances are also categorized in four schedules.  Classification is determined according to dependence creating properties, the potential level of abuse and the therapeutic value of the substances.  Any substances included in the four schedules must be licensed by the governments for manufacture, trade and distribution with supply or dispensing only being possible under legal authority.

The 1988 Convention was designed to deal with the growth of international trafficking in illegal substances in the 1970s and 1980s, since the earlier international instruments only dealt with the issue in a limited fashion. It provides comprehensive measures against drug trafficking, including provisions on money laundering, asset seizure, agreements on mutual legal assistance and the diversion of precursor chemicals.  In a similar manner to its sister treaties, annexed to the 1988 Convention are two lists, in this case termed tables rather than schedules.  These tables list substances frequently used in the illicit manufacture of narcotic drugs or psychotropic substances.  The Convention also tightened the control regime considerably by moving it to incorporate drug demand.  Both the 1961 as amended by the 1972 Protocol and the 1971 Conventions required application of criminal policy measures only on the supply side of the drug problem. While the 1988 Convention was mainly concerned with the illicit supply of drugs, one paragraph concerned itself with the individual drug user.  Article 3 (2) requires each party to make the possession of drugs for personal consumption a criminal offence under their domestic law, and as the Commentary on the United Nations Convention against Illicit Trafficking in Narcotic Drugs and Psychotropic Substances 1988 suggests, this “amounts in fact also to a penalisation of personal consumption.” (United Nations, 1998: 80).