Single Convention on Narcotic Drugs

The Single Convention on Narcotic Drugs is the international treaty against illicit manufacture and trafficking of narcotic drugs that forms the bedrock of the global drug control regime. Previous treaties had only controlled opium, coca, and derivatives such as morphine and heroin. The Single Convention, adopted in 1961, consolidated those treaties, broadening their scope to include cannabis and allow control of any drugs with similar effects to those specified in the treaty. The Commission on Narcotic Drugs and the World Health Organization were empowered to add, remove, and transfer drugs among the treaty's four Schedules of controlled substances. The International Narcotics Control Board was put in charge of administering controls on drug production, international trade, and dispensation. The United Nations Office on Drugs and Crime (UNODC) was delegated the Board's day-to-day work of monitoring the situation in each country and working with national authorities to ensure compliance with the Single Convention. This treaty has since been supplemented by the Convention on Psychotropic Substances, which controls LSD, Ecstasy, and other psychoactive pharmaceuticals, and the United Nations Convention Against Illicit Traffic in Narcotic Drugs and Psychotropic Substances, which strengthens provisions against money laundering and other drug-related offenses.

Influence on domestic legislation


Since the Single Convention is not self-executing, Parties must pass laws to carry out its provisions. The United Nations Office on Drugs and Crime works with countries' legislatures to ensure compliance. As a result, most of the national drug statutes in the UNODC's legal library share a high degree of conformity with the Single Convention and its supplementary treaties, the 1971 Convention on Psychotropic Substances and the 1988 United Nations Convention Against Illicit Traffic in Narcotic Drugs and Psychotropic Substances.

The Single Convention has been extremely influential in standardizing national drug control laws. In particular, the United States' Controlled Substances Act of 1970 and the United Kingdom's Misuse of Drugs Act 1971 were designed to fulfill treaty obligations. Both Acts include analogous schemes of drug Scheduling, along with similar procedures for adding, removing, and transferring drugs among the Schedules. The Controlled Substances Act follows the Single Convention's lead in granting a public health authority a central role in drug Scheduling decisions. It also includes a provision mandating that federal authorities control all drugs of abuse at least as strictly as required by the Single Convention(21 U.S.C. § 811(d)).

As of January 2005, the Single Convention had 180 Parties.

History
The League of Nations adopted several drug control treaties prior to World War II specifying uniform controls on addictive drugs such as cocaine, opium, and its derivatives. However, the lists of substances to be controlled were fixed in the treaties' text; consequently, the conventions had to periodically be amended or superseded by new treaties in order to keep up with advances in chemistry. The cumbersome process of conference and state-by-state ratification could take decades.

A Canadian Senate committee report notes, "The work of consolidating the existing international drug control treaties into one instrument began in 1948, but it was 1961 before an acceptable third draft was ready". That year, the UN Economic and Social Council convened a plenipotentiary conference of 73 nations for the adoption of a single convention on narcotic drugs. Canadian William B. McAllister, Q.C., notes that the participating states organized themselves into five distinct caucuses: These competing interests, after more than eight weeks of negotiations, finally produced a compromise treaty. Several controls were watered down; for instance, the proposed mandatory embargoes on nations failing to comply with the treaty became recommendatory. The 1953 New York Opium Protocol, which had not yet entered into force, limited opium production to seven countries; the Single Convention lifted that restriction, but instituted other regulations and put the International Narcotics Control Board in charge of monitoring their enforcement. A compromise was also struck that allowed heroin and some other drugs classified as particularly dangerous to escape absolute prohibition.
 * Organic states  group: As producers of the organic raw materials for most of the global drug supply, these countries had been the traditional focus of international drug control efforts. They were open to socio-cultural drug use, having lived with it for centuries. While India, Turkey, Pakistan and Burma took the lead, the group also included the coca-producing states of Indonesia and the Andean region of South America, the opium- and cannabis-producing countries of South and Southeast Asia, and the cannabis-producing  states in the Horn of Africa. They favored weak controls because existing restrictions on production and export had directly affected large segments of their  domestic population and industry. They supported national control efforts based on local conditions and were wary of strong international control bodies under the UN. Although essentially powerless to fight the prohibition philosophy directly, they effectively forced a compromise by working together to dilute the treaty language with exceptions, loopholes and  deferrals. They also sought development aid to compensate for losses caused by strict controls.
 * Manufacturing states group: This group included primarily Western industrialized nations, the key players being the United States, the United Kingdom, Canada, Switzerland, the Netherlands, West Germany, and Japan. Having no cultural affinity for organic drug use and being faced with the effects that drug abuse was having on their citizens, they advocated very stringent controls on the production of organic raw materials and on illicit trafficking. As the principal manufacturers  of synthetic psychotropics, and backed by a determined industry lobby, they forcefully opposed undue restrictions on medical research or the production and distribution of manufactured drugs. They favored strong supranational control bodies as long as they continued to exercise de facto control over such bodies. According to W.B. McAllister's Drug Diplomacy in the Twentieth Century, their strategy was essentially to "shift as much of the regulatory burden as possible to the raw-material-producing states while retaining as much of their own freedom as possible."
 * Strict control group: These were essentially non-producing and non-manufacturing states with no direct economic stake in the drug trade. The key members were France, Sweden, Brazil, and the Republic of China. Most of the states in this group were culturally opposed to drug use and suffered from abuse problems. They favored restricting drug use to medical and scientific purposes and were willing to sacrifice a degree of national sovereignty to ensure the effectiveness of supranational control bodies. They were forced to moderate their demands in order to secure the widest possible agreement.
 * Weak control group: This group was led by the Soviet Union and often included its allies in Europe, Asia and Africa. They considered drug control a purely internal issue and adamantly opposed any intrusion on national sovereignty, such as independent inspections. With little interest in the drug trade and minimal domestic abuse problems, they refused to give any supranational body excessive power, especially over internal decision-making.
 * Neutral group: This was a diverse group including most of the African countries,  Central America, sub-Andean South America, Luxembourg and the Vatican. They had no strong interest in the issue apart from ensuring their own access to sufficient drug supplies. Some voted with political blocs, others were willing to trade votes, and others were  truly neutral and could go either way on the control issue depending on the persuasive power of the arguments presented. In general, they supported compromise with a view to obtaining the broadest possible agreement.

The Single Convention created four Schedules of controlled substances and a process for adding new substances to the Schedules without amending the treaty. The Schedules were designed to have significantly stricter regulations than the two drug "Groups" established by predecessor treaties. For the first time, cannabis was added to the list of internationally controlled drugs. In fact, regulations on the cannabis plant – as well as the opium poppy, the coca bush, poppy straw and cannabis leaves – were embedded in the text of the treaty, making it impossible to deregulate them through the normal Scheduling process. A 1962 issue of the Commission on Narcotic Drugs' Bulletin on Narcotics proudly announced that "after a definite transitional period, all non-medical use of narcotic drugs, such as opium smoking, opium eating, consumption of cannabis (hashish, marijuana) and chewing of coca leaves, will be outlawed everywhere. This is a goal which workers in international narcotics control all over the world have striven to achieve for half a century".

An August 3, 1962 Economic and Social Council resolution ordered the issuance of the Commentary on the Single Convention on Narcotic Drugs. The legal commentary was created by the United Nations Secretary-General's staff (specifically, Adolf Lande, former Secretary of the Permanent Central Narcotics Board and Drug Supervisory Body), operating under a mandate to give "an interpretation of the provisions of the Convention in the light of the relevant conference proceedings and other material". The Commentary contains the Single Convention's legislative history and is an invaluable aid to interpreting the treaty.

The Single Convention entered into force on December 13, 1964, having met Article 41's requirement of 40 ratifications. As of January 1, 2005, 180 states were Parties to the treaty. Others, such as Cambodia, have committed to becoming Parties.

On May 21, 1971, the UN Economic and Social Council called a conference of plenipotentiaries to consider amendments to the Single Convention. The conference met at the United Nations Office at Geneva from March 6 to March 24, 1972, producing the 1972 Protocol Amending the Single Convention on Narcotic Drugs. The amendments entered into force on August 8, 1975.

On November 11, 1990, mechanisms for enforcing the Single Convention were expanded significantly by the entry into force of the United Nations Convention Against Illicit Traffic in Narcotic Drugs and Psychotropic Substances, which had been signed at Vienna on December 20, 1988. The Preamble to this treaty acknowledges the inadequacy of the Single Convention's controls to stop "steadily increasing inroads into various social groups made by illicit traffic in narcotic drugs and psychotropic substances". The new treaty focuses on stopping organized crime by providing for international cooperation in apprehending and convicting gangsters and starving them of funds through forfeiture, asset freezing, and other methods. It also establishes a system for placing precursors to Scheduled drugs under international control. Some non-Parties to the Single Convention, such as Andorra, belong to this treaty and thus are still under the international drug control regime.

Medical and other drug uses
The Single Convention repeatedly affirms the importance of medical use of controlled substances. The Preamble notes that "the medical use of narcotic drugs continues to be indispensable for the relief of pain and suffering and that adequate provision must be made to ensure the availability of narcotic drugs for such purposes". Articles 1, 2, 4, 9, 12, 19, and 49 contain provisions relating to "medical and scientific" use of controlled substances. In almost all cases, parties are permitted to allow dispensation and use of controlled substances under a prescription, subject to record-keeping requirements and other restrictions.

The Single Convention unambiguously condemns drug addiction, however, stating that "addiction to narcotic drugs constitutes a serious evil for the individual and is fraught with social and economic danger to mankind". It takes a prohibitionist approach to the problem of drug addiction, attempting to stop all non-medical, non-scientific use of narcotic drugs. Article 4 requires nations to limit use and possession of drugs to medicinal and scientific purposes. Article 49 allows countries to phase out coca leaf chewing, opium smoking, and other traditional drug uses gradually, but provides that "the use of cannabis for other than medical and scientific purposes must be discontinued as soon as possible."

The discontinuation of these prohibited uses is intended to be achieved by cutting off supply. Rather than calling on nations to prosecute drug users, the treaty focuses on traffickers and producers. As of March 2005, 116 drugs were controlled under the Single Convention.

Penal provisions
Article 36 requires Parties to criminalize "cultivation, production, manufacture, extraction, preparation, possession, offering, offering for sale, distribution, purchase, sale, delivery on any terms whatsoever, brokerage, dispatch, dispatch in transit, transport, importation and exportation of drugs contrary to the provisions of this Convention," as well as "[i]ntentional participation in, conspiracy to commit and attempts to commit, any of such offences, and preparatory acts and financial operations in connexion with the offences referred to in this article".

The Article also provides for extradition of drug offenders, although a Party has a right to refuse to extradite a suspect if "competent authorities consider that the offense is not sufficiently serious." A 1971 amendment to the Article grants nations the discretion to substitute "treatment, education, after-care, rehabilitation and social reintegration" for criminal penalties if the offender is a drug abuser. A loophole in the Single Convention is that it requires Parties to place anti-drug laws on the books, but does not clearly mandate their enforcement, except in the case of drug cultivation.

Drug enforcement varies widely between nations. Many European countries, including the United Kingdom, Germany, and, most famously, the Netherlands, do not prosecute all petty drug offenses. Dutch coffee shops are allowed to sell small amounts of cannabis to consumers. However, the Ministerie van Volksgezondheid's report, Drugs Policy in the Netherlands, notes that large-scale "[p]roduction and trafficking are dealt with severely under the criminal law, in accordance with the UN Single Convention. Each year the Public Prosecutions Department deals with an average of 10,000 cases involving infringements of the Opium Act". Some of the most severe penalties for drug trafficking are handed down in certain Asian countries, such as Malaysia, which mandate capital punishment for offenses involving amounts over a certain threshold. Singapore mandates the death penalty for trafficking in 15 grams (half an ounce) of heroin, 30 grams of cocaine or 500 grams of cannabis. Most nations, such as France and the United States, find a middle ground, imposing a spectrum of sanctions ranging from probation to life imprisonment for drug offenses.

The Single Convention's penal provisions frequently begin with clauses such as "Subject to its constitutional limitations, each Party shall . . ." Thus, if a nation's constitution prohibited instituting the criminal penalties called for by the Single Convention, those provisions would not be binding on that country. However, Professor Cindy Fazey's A Growing Market: The Domestic Cultivation of Cannabis points out, "Whilst this strategy may be practical politics for some countries, critics will ask why it has taken almost half a century to discover that the UN conventions conflict with a constitutional principle. The argument is particularly difficult to deploy for countries like Britain, where constitutional principles are not formalized or codified to any significant degree." However the current move in Switzerland to enshrine cannabis decriminalization in the national constitution by popular initiative could profit from this rule.

Possession for personal use
It is unclear whether or not the treaty requires criminalization of drug possession for personal use. The treaty's language is ambiguous, and a ruling by the International Court of Justice would probably be required to settle the matter decisively. However, several commissions have attempted to tackle the question. With the exception of the Le Dain Commission, most have found that states are allowed to legalize possession for personal use.

The Canadian Le Dain Commission of Inquiry into the Non-Medical Use of Drugs' 1973 report cites circumstantial evidence suggesting that states must prohibit possession for personal use:
 * It has generally been assumed that "possession" in Article 36 includes possession for use as well as possession for the purpose of trafficking. This is a reasonable inference from the terms of Article 4, which obliges the parties "to limit exclusively to medical and scientific purposes the production, manufacture, export, import, distribution of, trade in, use and possession of drugs." There is also Article 33, which provides that "The Parties shall not permit the possession of drugs except under legal authority." [...] On the face of Article 26 it would not be unreasonable to argue that what is contemplated is possession for the purpose of trafficking rather than possession for use, and that the requirements of the article are satisfied if the former kind of possession is made a penal offense. The prevailing view, however, is that the word "possession" in Article 36 includes simple possession for use.

However, LeDain himself concludes

''The costs to a significant number of individuals, the majority of whom are young people, and to society generally, of a policy of prohibition of simple possession are not justified by the potential for harm of cannabis and the additional influence which such a policy is likely to have upon perception of harm, demand and availability. We, therefore, recommend the repeal of the prohibition against the simple possession of cannabis.''LeDain report

The Canadian Department of National Health and Welfare's 1979 report, The Single Convention and Its Implications for Canadian Cannabis Policy, counters with circumstantial evidence to the contrary:
 * The substantive argument in support of simple possession falling outside the scope of Article 36 is founded on the assumption that it is intended to insure a penal response to the problem of illicit trafficking rather than to punish drug users who do not participate in the traffic. (See United Nations, 1973:112; Noll, 1977:44–45) The Third Draft of the Single Convention, which served as the working document for the 1961 Plenipotentiary Conference, contained a paragraph identical to that which now appears as Article 36, subparagraph 1(a). This paragraph was included in a chapter entitled Measures Against Illicit Traffickers, but the format by which the Third Draft was divided into chapters was not transferred to the Single Convention, and this, apparently, is the sole reason why this chapter heading, along with all others, was deleted. (See United Nations, 1973:112) Article 36 is still located in that part of the Convention concerned with the illicit trade, sandwiched between Article 35 (Action Against the Illicit Traffic) and Article 37 (Seizure and Confiscation). In addition, it should be noted that the word "use," suggesting personal consumption rather than trafficking, appears in conjunction with "possession" in Article 4 (which pertains to non-penal "general obligations"), but not in the penal provisions of Article 36.

The Sackville Commission of South Australia concluded in 1978 that:
 * . . . the Convention does not require signatories to make either use or possession for personal use punishable offenses ... This is because ‘use’ is not specifically covered by Article 36 and the term ‘possession’ in that Article and elsewhere can be read as confined to possession for the purpose of dealing".

The American National Commission on Marihuana and Drug Abuse reached a similar conclusion in 1972, finding "that the word 'possession' in Article 36 refers not to possession for personal use but to Possession as a link in illicit trafficking."

The Canadian Department of National Health and Welfare report cites the Commentary itself in backing up its interpretation:
 * The official Commentary on the Single Convention on Narcotic Drugs 1961, as prepared by the office of the U.N. Secretary-General, adopts a permissive interpretation of possession in Article 36. It notes that whether or not the possession of drugs (including prohibited forms of cannabis) for personal use requires the imposition of penal sanctions is a question which may be answered differently in different countries. Further, the Commentary notes that parties which interpret Article 36 as requiring a punitive legal response to simple possession, may undoubtedly choose not to provide for imprisonment of persons found in such possession, but to impose only minor penalties such as fines or even censure (since possession of a small quantity of drugs for personal consumption may be held not to be a serious offense under article 36... and only a serious offense is liable to adequate punishment particularly by imprisonment or other penalties of deprivation of liberty.

The Bulletin on Narcotics attempted to tackle the question in 1977:
 * Since some confusion and misunderstanding had existed in the past and some instances still persist in respect of the legal position laid down in the international treaties concerning the relationship between penal sanctions and drug abuse, some clarifying remarks are called for. These were already offered at the XIth International Congress on Penal Law. 5 They were reiterated at the Fifth United Nations Congress on the Prevention of Crime and the Treatment of Offenders. 6 The international treaties in no way insist on harsh penal sanctions with regard to drug abuse, as is sometimes alleged by persons criticising the international drug control system; the treaties are much more subtle and flexible than sometimes interpreted.
 * First of all, Article 4 of the Single Convention contains the general obligations for Parties to this Convention to "take such legislative and administrative measures as may be necessary, subject to the provisions of this Convention, to limit exclusively to medical and scientific purposes the production, manufacture, export, import, distribution of, trade in, use and possession of drugs." From the contents of this provision it is clear that use of drugs and their possession for personal consumption has also to be limited by legislation and administrative measures exclusively to medical and scientific purposes. Consequently, "legalization" of drugs in the sense of making them freely available for non-medical and non-scientific purposes-as it is sometimes demanded by public mass media and even experts in discussions on the subject-is without any doubt excluded and unacceptable under the present international drug control system as established by the international treaties. The question, however, remains whether Parties are obliged by the international treaties to apply penal sanctions for unauthorized use and unauthorized possession of drugs for personal consumption. It is on this point that confusion still exists and clarification is needed.
 * It is a fact that "use" (or "personal consumption") is not enumerated amongst the punishable offences in accordance with paragraph 1 of Article 36 of the Single Convention. Although, as mentioned above, Parties are required to limit the use of drugs exclusively to medical and scientific purposes, the Single Convention does not require them to attain the goal by providing penal sanctions for unauthorized "use" or "personal consumption" of drugs.
 * Unauthorized "possession" of drugs is mentioned in paragraph 1 of Article 36, but from the context it is clear that, as stated in the Official Commentary by the Secretary-General of the United Nations, "possession" of drugs for personal consumption is not to be considered a "punishable offence" by a Party to the Single Convention. The whole international drug control system envisages in its penal provisions the illicit traffic in drugs; this also holds true for the 1972 Protocol Amending the Single Convention and for the 1971 Convention on Psychotropic Substances. As there is no obligation to provide penal sanctions for "use" in the sense of personal consumption and "possession" of drugs for personal consumption, any criticism levelled against the international drug control system by protagonists in favour of the so-called "liberalization" or decriminalization or "de-penalization" of use and possession of drugs for personal consumption is quite beside the point.

Schedules of drugs
The Single Convention's Schedules of drugs range from most restrictive to least restrictive, in this order: Schedule IV, Schedule I, Schedule II, Schedule III. The list of drugs initially controlled was annexed to the treaty. Article 3 states that in order for a drug to be placed in a Schedule, the World Health Organization must make the findings required for that Schedule, to wit:
 * Schedule I – The substance is liable to similar abuse and productive of similar ill effects as the drugs already in Schedule I or Schedule II, or is convertible into a drug.
 * Schedule II – The substance is liable to similar abuse and productive of similar ill effects as the drugs already in Schedule I or Schedule II, or is convertible into a drug.
 * Schedule III – The preparation, because of the substances which it contains, is not liable to abuse and cannot produce ill effects; and the drug therein is not readily recoverable.
 * Schedule IV – The drug, which is already in Schedule I, is particularly liable to abuse and to produce ill effects, and such liability is not offset by substantial therapeutic advantages.

Schedule I, according to the Commentary, is the category of drugs whose control provisions "constitute the standard regime under the Single Convention". The principal features of that regime are:
 * Limitation to medical and scientific purposes of all phases of narcotics trade (manufacture, domestic trade, both wholesale and retail, and international trade) in, and of the possession and use of, drugs;
 * Requirement of governmental authorization (licensing or state ownership) of participation in any phase of the narcotics trade and of a specific authorization (import and export authorization) of each individual international transaction;
 * Obligation of all participants in the narcotics trade to keep detailed records of their transactions in drugs;
 * Requirement of a medical prescription for the supply or dispensation of drugs to individuals;
 * A system of limiting the quantities of drugs available, by manufacture or import or both, in each country and territory, to those needed for medical and scientific purposes.

Schedule II drugs are regulated only slightly less strictly than Schedule I drugs. The Commentary confirms, "Drugs in Schedule II are subject to the same measures of control as drugs in Schedule I, with only a few exceptions":
 * The drugs are not subject to the provisions of Article 30, paragraphs 2 and 5, as regards the retail trade.
 * Governments are thus not bound to prevent the accumulation of drugs in Schedule II in the possession of retail distributors, in excess of the quantities required for the normal conduct of business.
 * Medical prescriptions for the supply or dispensation of these drugs to individuals are not obligatory.
 * Such drugs are also exempted from the provision – which in fact is no more than a suggestion – concerning the use of official prescription forms in the shape of counterfoil books issued by the competent governmental authorities or by authorized professional associations.
 * Parties to the Single Convention need not require that the label under which a drug in Schedule II is offered for sale in the retail trade show the exact content by weight or percentage.

Schedule III "contains preparations which enjoy a privileged position under the Single Convention, i.e. are subject to a less strict regime than other Preparations," according to the Commentary. Specifically:
 * Government authorizations are not required for each import or export of preparations in Schedule III. The import certificate and export authorization system laid down in Article 31, paragraphs 4 to 15, which governs the international transactions in drugs and their preparations, does not apply to the preparations in Schedule III.
 * The only estimates and statistical returns that a Party need furnish to the INCB in reference to Schedule III preparations are estimates of the quantities of drugs to be utilized for the compounding of preparations in Schedule III, and information on the amounts of drugs actually so used.

Schedule IV is the category of drugs, such as heroin, that are considered to have "particularly dangerous properties" in comparison to other drugs. According to Article 2, "The drugs in Schedule IV shall also be included in Schedule I and subject to all measures of control applicable to drugs in the latter Schedule" as well as whatever "special measures of control"; each Party deems necessary. This is in contrast to the U.S. Controlled Substances Act, which has five Schedules ranging from Schedule I (most restrictive) to Schedule V (least restrictive), and the Convention on Psychotropic Substances, which has four Schedules ranging for Schedule I (most restrictive) to Schedule IV (least restrictive).

Under certain circumstances, Parties are required to limit Schedule IV drugs to research purposes only:
 * (b) A Party shall, if in its opinion the prevailing conditions in its country render it the most appropriate means of protecting the public health and welfare, prohibit the production, manufacture, export and import of, trade in, possession or use of any such drug except for amounts which may be necessary for medical and scientific research only, including clinical trials therewith to be conducted under or subject to the direct supervision and control of the Party.

The Commentary explains two situations in which this provision would apply:
 * For a considerable period of time - and still at the time of writing - there has been no significant diversion of legally manufactured drugs from legal trade into illicit channels; but if a Government were unable to prevent such a diversion of drugs in Schedule IV, a situation would arise in which the measures of prohibition mentioned in subparagraph (b) would be "the most appropriate means of protecting the public health and welfare". Whether this was or was not the case would be left to the judgement of the Party concerned whose bona fide opinion on this matter could not be challenged by any other Party.
 * Another situation in which measures of prohibition would be "appropriate" for the protection of public health and welfare might exist where the members of the medical profession administered or prescribed drugs in Schedule IV in an unduly extensive way, and other less radical measures, such as warnings by public authorities, professional associations or manufacturers, were ineffective. It may however be assumed that such a situation could rarely if ever arise.

The Commentary notes that "Whether the prohibition of drugs in Schedule IV (Cannabis and cannabis resin, desomorphine, heroin, ketobemidone) should be mandatory or only recommended was a controversial question at the Plenipotentiary Conference." The provision adopted represents "a compromise which leaves prohibition to the judgement, though theoretically not to the discretion, of each Party." The Parties are required to act in good faith in making this decision, or else they will be in violation of the treaty.

Power structure
The Single Convention gives the UN Economic and Social Council's Commission on Narcotic Drugs (CND) power to add or delete drugs from the Schedules, in accordance with the World Health Organization's findings and recommendations. Any Party to the treaty may request an amendment to the Schedules, or request a review of the Commission's decision. The Economic and Social Council is the only body that has power to confirm, alter, or reverse the CND's scheduling decisions. The United Nations General Assembly can approve or modify any CND decision, except for scheduling decisions.

The CND's annual meeting serves as a forum for nations to debate drug policy. At the 2005 meeting, France, Germany, the Netherlands, Canada, Australia and Iran rallied in opposition to the UN's zero-tolerance approach in international drug policy. Their appeal was vetoed by the United States, while the United Kingdom delegation remained reticent. Meanwhile, U.S. Office of National Drug Control Policy Director John Walters clashed with United Nations Office on Drugs and Crime Executive Director Antonio Maria Costa on the issue of needle exchange programs. Walters advocated strict prohibition, while Costa opined, "We must not deny these addicts any genuine opportunities to remain HIV-negative".

The International Narcotics Control Board (INCB) is mandated by Article 9 of the Single Convention to "endeavour to limit the cultivation, production, manufacture and use of drugs to an adequate amount required for medical and scientific purposes, to ensure their availability for such purposes and to prevent illicit cultivation, production and manufacture of, and illicit trafficking in and use of, drugs." The INCB administers the estimate system, which limits each nation's annual production of controlled substances to the estimated amounts needed for medical and scientific purposes.

Article 21 provides that "the total of the quantities of each drug manufactured and imported by any country or territory in any one year shall not exceed the sum of" the quantity:
 * Consumed, within the limit of the relevant estimate, for medical and scientific purposes;
 * Used, within the limit of the relevant estimate, for the manufacture of other drugs, of preparations in Schedule Ill, and of substances not covered by this Convention;''
 * Exported;
 * Added to the stock for the purpose of bringing that stock up to the level specified in the relevant estimate; and
 * Acquired within the limit of the relevant estimate for special purposes.

Article 21 bis, added to the treaty by a 1971 amendment, gives the INCB more enforcement power by allowing it to deduct from a nation's production quota of cannabis, opium, and coca the amounts it determines have been produced within that nation and introduced into the illicit traffic. This could happen as a result of failing to control either illicit production or diversion of licitly produced opium to illicit purposes. In this way, the INCB can essentially punish a narcotics-exporting nation that does not control its illicit traffic by imposing an economic sanction on its medicinal narcotics industry.

The Single Convention exerts power even over those nations that have not ratified it. The International Narcotics Board states:
 * The fact that the system generally works well is mainly due to the estimates system that covers all countries whether or not parties to the Convention. Countries are under an obligation not to exceed the amounts of the estimates confirmed or established by the INCB.

Article 14 authorizes the INCB to recommend an embargo on imports and exports of drugs from any noncompliant nations. The INCB can also issue reports critical of noncompliant nations, and forward those reports to all Parties. This happened when the United Kingdom reclassified cannabis from Class B to class C, eliminating the threat of arrest for possession. See Cannabis reclassification in the United Kingdom.

The most controversial decisions of the INCB are those in which it assumes the power to interpret the Single Convention. Germany, the Netherlands, Switzerland, and Spain continue to experiment with medically supervised injection rooms, despite the INCB's objections that the Single Convention's allowance of "scientific purposes" is limited to clinical trials of pharmaceutical grade drugs and not public health interventions. These European nations have more leverage to disregard the Board's decisions because they are not dependent on licit psychoactive drug exports (which are regulated by the Board). As international lawyer Bill Bush notes, "Because of the Tasmanian opium poppy industry, Australia is more vulnerable to political pressure than, say, Germany".

The INCB is an outspoken opponent of drug legalization. Its 2002 report rejects a common argument for drug reform, stating, "Persons in favour of legalizing illicit drug use argue that drug abusers should not have their basic rights violated; however, it does not seem to have occurred to those persons that drug abusers themselves violate the basic rights of their own family members and society." The report dismisses concerns that drug control conflicts with principles of limited government and self-determination, arguing, "States have a moral and legal responsibility to protect drug abusers from further self-destruction." The report takes a majoritarian view of the situation, declaring, "Governments must respect the view of the majority of lawful citizens; and those citizens are against illicit drug use".

Article 48 designates the International Court of Justice as the arbiter of disputes about the interpretation or application of the Single Convention, if mediation, negotiation, and other forms of alternative dispute resolution fail.

Limitation of scope
The Single Convention allows only drugs with morphine-like, cocaine-like, and cannabis-like effects to be added to the Schedules. The strength of the drug is not relevant; only the similarity of its effects to the substances already controlled. For instance, etorphine and acetorphine were considered sufficiently morphine-like to fall under the treaty's scope, although they are many times more potent than morphine. However, according to the Commentary:
 * The Office of Legal Affairs of the United Nations ruled, in an opinion given to the Commission on Narcotic Drugs at its twenty-third session, that barbiturates, tranquillizers and amphetamines were outside the scope of the Single Convention. It pointed out that there was an understanding at all stages of the drafting of the Single Convention, in particular at the Plenipotentiary Conference of 1961 which adopted that treaty, that the Convention was not applicable to these three types of substances, although the effects of amphetamines have some degree of similarity to cocaine, and those of barbiturates and tranquillizers to morphine.

Since cannabis is a hallucinogen (although some dispute this), the Commentary speculates that mescaline, psilocybin, tetrahydrocannabinol, and LSD could have been considered sufficiently cannabis-like to be regulated under the Single Convention; however, it opines, "It appears that the fact that the potent hallucinogenics whose abuse has spread in recent years have not been brought under international narcotics control does not result from legal reasons, but rather from the view of Governments that a regime different from that offered by the Single Convention would be more adequate." That different regime was instituted by the 1971 Convention on Psychotropic Substances. The Convention on Psychotropic Drugs' scope can include any drug not already under international control if the World Health Organization finds that: The reason for sharply limiting the scope of Single Convention to a few types of drugs while letting the Convention on Psychotropic Drugs cover the rest was concern for the interests of industry. Professor Cindy Fazey's The Mechanics and Dynamics of the UN System for International Drug Control explains, "It should be noted that concerted efforts by drug manufacturing nations and the pharmaceutical industry ensured that the controls on psychotropics in the 1971 treaty were considerably looser than those applied to organic drugs in the Single Convention".
 * The substance has the capacity to produce "[a] state of dependence" AND "[c]entral nervous system stimulation or depression, resulting in hallucinations or disturbances in motor function or thinking or behaviour or perception or mood"; or
 * The substance has the capacity to produce similar abuse and similar ill effects as LSD or one of the other controlled substances enumerated in Convention; or
 * There is sufficient evidence that the substance is being or is likely to be abused so as to constitute a public health and social problem warranting the placing of the substance under international control.

A March 24, 2003 European Parliament committee report noted the disparity in how drugs are regulated under the two treaties:
 * The 1971 Convention, which closely resembles the Single Convention, establishes an international control which is clearly less rigorous for the so-called 'psychotropic' substances, generally produced by the pharmaceutical industry. . . The parallel existence of the Single Convention and the 1971 Convention have led to certain illogical effects such as the fact that a plant (cannabis) containing at most 3% of a principal element is dealt with more severely than the pure substance at 100% (tetrahydrocannabinol or THC).

For this reason, the European Parliament, Transnational Radical Party, and other organizations have proposed removing cannabis and other drugs from the Single Convention and scheduling them under the Convention on Psychotropic Substances.

Furthermore, the provisions of the Single Convention regarding the national supply and demand of opium to make morphine contribute to the global shortage of essential poppy-based pain relief medicines. According to the Convention, governments can only request raw poppy materials according to the amount of poppy-based medicines used in the two preceding years. Consequently, in countries where underprescription is chronic due to the high prices of morphine and lack of availability and medical training in the prescription of poppy-based drugs, it is impossible to demand enough raw poppy materials from the INCB, as the Convention's regulating body, to meet the country's pain relief needs. As such, 77% of the world's poppy-based medicine supplies are used by only six countries (See: Fischer, B J. Rehm, and T Culbert, “Opium based medicines: a mapping of global supply, demand and needs” in Spivack D. (ed.) Feasibility Study on Opium Licensing in Afghanistan, Kabul, 2005. p.85–86. ). Many critics of the Convention cite this as one of its primary limitations and the World Health Organisation is currently attempting to increase prescription of poppy-based drugs and to help governments of emerging countries in particular alter their internal regulations to be able to demand poppy-based medicines according to the Convention's provisions (see the WHO "Assuring Availability of Opoid Analgesics for Palliative Care"). The Senlis Council, a European drug policy thinktank, proposes creating a second-tier supply system that would complement the existing system without altering the balance of its relatively closed supply and demand system. The Council, who support licensing poppy cultivation in Afghanistan to create Afghan morphine, believe the opium supply in this country could go a long way to easing the pain relief needs of sufferers in emerging countries by producing a cheap poppy-based medicine solution (see [The Senlis Council]: "Poppy for Medicine".

Cultivation
The Single Convention places the same restrictions on cannabis cultivation that it does on opium cultivation. Article 23 and Article 28 require each Party to establish a government agency to control cultivation. Cultivators must deliver their total crop to the agency, which must purchase and take physical possession of them within four months after the end of harvest. The agency then has the exclusive right of "importing, exporting, wholesale trading and maintaining stocks other than those held by manufacturers."

In the United States, the National Institute on Drug Abuse fulfills that function. NIDA administers a contract with the University of Mississippi to grow a 1.5 acre (6,000 m²) crop of cannabis every other year; that supply comprises the only licit source of cannabis for medical and research purposes in the United States. Similarly, in 2000, Prairie Plant Systems was awarded a five-year contract to grow cannabis in the Flin Flon mine for Health Canada, that nation's licit cannabis cultivation authority.

Article 28 specifically excludes industrial hemp from these regulations, stating, "This Convention shall not apply to the cultivation of the cannabis plant exclusively for industrial purposes (fibre and seed) or horticultural purposes." Hemp-growing countries include China, Romania, France, Germany, Netherlands, England, and Hungary. Hemp cultivation is theoretically legal in the United States, but tight Drug Enforcement Administration restrictions would likely make it unprofitable.

Rescheduling proposals
There is some controversy over whether cannabis is "particularly liable to abuse and to produce ill effects" and whether that "liability is not offset by substantial therapeutic advantages," as required by Schedule IV criteria. In particular, the discovery of the cannabinoid receptor system in the late 1980s revolutionized scientific understanding of cannabis' effects, and much anecdotal evidence has come to light about the drug's medical uses. The Canadian Senate committee's report notes,
 * At the U.S.’s insistence, cannabis was placed under the heaviest control regime in the Convention, Schedule IV. The argument for placing cannabis in this category was that it was widely abused. The WHO later found that cannabis could have medical applications after all, but the structure was already in place and no international action has since been taken to correct this anomaly.

The Commentary points out the theoretical possibility of removing cannabis from Schedule IV:
 * Those who question the particularly harmful character of cannabis and cannabis resin may hold that the Technical Committee of the Plenipotentiary Conference was under its own criteria not justified in placing these drugs in Schedule IV; but the approval of the Committee's action by the Plenipotentiary Conference places this inclusion beyond any legal doubt. Should the results of the intensive research which is at the time of this writing being undertaken on the effects of these two drugs so warrant, they could be deleted from Schedule IV, and these two drugs, as well as extracts and tinctures of cannabis, could be transferred from Schedule I to Schedule II.

Cindy Fazey, former Chief of Demand Reduction for the United Nations Drug Control Programme, has pointed out that it would be nearly impossible to loosen international cannabis regulations. Even if the Commission on Narcotic Drugs removed cannabis from Schedule IV of the Single Convention, prohibitions against the plant would remain imbedded in Article 28 and other parts of the treaty. Fazey cited amendment of the Articles and state-by-state denunciation as two theoretical possibilities for changing cannabis' international legal status, while pointing out that both face substantial barriers. See Cannabis reform at the international level.

In a 2002 interview, INCB President Philip O. Emafo condemned European cannabis decriminalization measures:
 * It is possible that the cannabis being used in Europe may not be the same species that is used in developing countries and that is causing untold health hazards to the young people who are finding themselves in hospitals for treatment. Therefore, the INCB's concern is that cannabis use should be restricted to medical and scientific purposes, if there are any. Countries who are party to the Single Convention need to respect the provisions of the conventions and restrict the use of drugs listed in Schedules I to IV to strictly medical and scientific purposes.

However, the European Parliament's Committee on Citizens' Freedoms and Rights, Justice and Home Affairs issued a report on March 24, 2003 criticizing the Single Convention's scheduling regime:
 * These schedules show that the main criterion for the classification of a substance is its medical use. In view of the principle according to which the only licit uses is those for medical or scientific purposes (art. 4), plants or substances deprived of this purpose are automatically considered as particularly dangerous. Such is the case for cannabis and cannabis resin which are classified with heroin in group IV for the sole reason that they lack therapeutic value. A reason which is in any event disputable, since cannabis could have numerous medical uses.

There have been several lawsuits over whether cannabis' Schedule IV status under the Single Convention requires total prohibition at the national level. The U.S. Congress enacted the Controlled Substances Act in 1970 to implement the treaty, placing cannabis in the Act's most tightly restricted category of drugs. In 1972, the National Organization for the Reform of Marijuana Laws filed a rescheduling petition under provisions of the Act. The government declined to initiate proceedings on the basis of their interpretation of U.S. treaty commitments. A federal Court ruled against the government and ordered them to process the petition (NORML v. Ingersoll 497 F.2d 654 (1974)). The government continued to rely on treaty commitments in their interpretation of scheduling related issues concerning the NORML petition, leading to another lawsuit (NORML v. DEA 559 F.2d 735 (1977)). In this decision, the Court made clear that the Act requires a full scientific and medical evaluation and the fulfillment of the rescheduling process before treaty commitments can be evaluated. See Cannabis rescheduling in the United States.

Cannabis leaves (as opposed to buds) are a special case. The Canadian Health Protection Branch's Cannabis Control Policy: A Discussion Paper found that, while the Single Convention requires nations to take measures against the misuse of, and illicit traffic in, cannabis buds, a ban is not required on licit production, distribution, and use of the leaves:
 * The Single Convention defines "cannabis" as the flowering or fruiting tops of the cannabis plant (excluding the seeds and leaves when not accompanied by the tops) from which the resin has not been extracted. (Art. 1, s-para. 1(b)) It is generally accepted that this definition permits the legalization of the leaves of the cannabis plant, provided that they are not accompanied by the flowering or fruiting tops. However, uncertainty arises by virtue of paragraph 3 of Article 28 which requires parties to the Convention to "adopt such measures as may be necessary to prevent the misuse of, and illicit traffic in, the leaves of the cannabis plant." In summary, it appears that parties are not obliged to prohibit the production, distribution and use of the leaves (since they are not drugs, as defined the Convention), although they must take necessary, although unspecified, measures to prevent their misuse and diversion to the illicit trade.

Predecessor treaties
Article 44 provided that the Single Convention's entry into force terminated several predecessor treaties, including:
 * The International Opium Convention, signed at The Hague on January 23, 1912;
 * The Agreement concerning the Manufacture of, Internal Trade in and Use of Prepared Opium, signed at Geneva on February 11, 1925;
 * The International Opium Convention, signed at Geneva on February 19, 1925;
 * The Convention for Limiting the Manufacture and Regulating the Distribution of Narcotic Drugs, signed at Geneva on July 13, 1931;
 * The Agreement for the Control of Opium Smoking in the Far East, signed at Bangkok on November 27, 1931;
 * The Protocol Amending the Agreements, Conventions and Protocols on Narcotic Drugs concluded at The Hague on 23 January 1912, at Geneva on 11 February 1925 and 19 February 1925, and 13 July 1931, at Bangkok on 27 November 1931 and at Geneva on 26 June 1936 (except as it affected the latter), signed at Lake Success on December 11, 1946;
 * The Protocol Bringing under International Control Drugs outside the Scope of the Convention of 13 July 1931 for Limiting the Manufacture and Regulating the Distribution of Narcotic Drugs, signed at Paris on November 19, 1948; and
 * The Protocol for Limiting and Regulating the Cultivation of the Poppy Plant, the Production of, International and Wholesale Trade in, and Use of Opium, signed at New York on June 23, 1953.

Supplementary treaties
The Single Convention is supplemented by two other major drug control treaties:
 * The Convention on Psychotropic Substances controls LSD, Ecstasy, and other drugs whose unique psychoactive effects exclude them from the scope of the Single Convention. It was signed at Vienna on February 21, 1971.


 * The United Nations Convention Against Illicit Traffic in Narcotic Drugs and Psychotropic Substances adds additional enforcement mechanisms for fighting drug traffickers, including asset forfeiture provisions. The Convention also establishes a system of drug precursor regulation, dividing them into two tables of listed chemicals. It was signed at Vienna on December 20, 1988.