1. An ECOSOC mandated study published in 1950 as the Report of the Commission of Enquiry on the Coca Leaf, recommends to suppress “the harmful habit of chewing coca” within a few years;
2. In 1952 the WHO Expert Committee on Drugs Liable to Produce Addiction concluded that “coca chewing comes so close to the characteristics of addiction ... that it must be defined and treated as an addiction” and advised this to the Commission on Narcotic Drugs.
3. Coca, together with cannabis and opium, became one of the main control targets of the 1961 Single Convention on Narcotic Drugs, including special restrictions on cultivation, proscribing the phasing out of traditional use within 25 years and listing the coca leaf as “a substance liable for abuse” in Schedule 1;
4. The 1988 Convention against Illicit Traffic in Narcotic Drugs and Psychotropic Substances forced states to criminalize coca, under article 3, paragraph 2: “Subject to its constitutional principles and the basic concepts of its legal system, each Party shall adopt such measures as may be necessary to establish as a criminal offence under its domestic law,when committed intentionally, the possession, purchase or cultivation of narcotic drugs or psychotropic substances for personal consumption contrary to the provisions of the 1961 Convention, the 1961Convention as amended or the 1971 Convention”, but it also makes an exemption for traditional use; Article 14 states: “Each Party shall take appropriate measures to prevent illicit cultivation of and to eradicate plants containing narcotic or psychotropic substances, such as opium poppy, coca bush and cannabis plants, cultivated illicitly in its territory”, but then continues saying that the “measures adopted shall respect fundamental human rights and shall take due account of traditional licit uses, where there is historic evidence of such use”. One official reservation was made, only by Bolivia, upon signing and confirmed upon ratification of this Convention to preserve the right to use coca leaf for traditional purposes.
5. The INCB annual report for 1994 stressed that: “The conflict between the provisions of the 1961 Convention and the views and legislation of countries where the use of the coca leaf is legal should be solved. There is a need to undertake a scientific review to assess the coca-chewing habit and the drinking of coca tea.” A supplement to the 1994 report dedicated one section to ‘Coca leaf: a need to clarify ambiguities’, calling for ”a need to examine the situation regarding State parties to the 1961 Convention that have made reservations under article 49 of that Convention. A true assessment of the habit of coca leaf chewing is urgently called for”.
6. In 1995 the WHO finished “the largest global study on cocaine use”, including one part on the use of coca leaf, concluding that "the use of coca leaves appears to have no negative health effects and has positive therapeutic, sacred and social functions for indigenous Andean populations", apparently one of the reasons the study was obstructed in a peer review process, and never published.
7. In September 2007 the UN adopts the Universal Declaration on the Rights of Indigenous Peoples, reflecting a global commitment to respect cultural traditions and medicinal practices of all indigenous populations. This recognition reflects a clear contradiction in international law regarding the legal status of traditional use of coca.
8. The government of Bolivia proposed to amend the 1961 Single Convention in March 2009, by removing two sub paragraphs of article 49 that bans coca leaf chewing. A US-led coalition presented objections within the 12 months period established by the procedure, and blocked the amendment.
9. In July 2011 Bolivia denounced the 1961 Single Convention, which came into effect in January 2012. Bolivia will reaccede the treaty on the 10 th of January 2013 with a new reservation that will only enter into force if two third of all parties to the Convention do not express objections. Whether Bolivia would decide to still reaccede in the unlikely case that the reservation is not accepted, remains to be seen.
10. In February 2012 Bolivia responded to the INCB annual report for 2011 preface, in which it was accused of threatening the integrity of the entire international drug control regime by using the rarely used but legitimate procedure of treaty denunciation and reaccession with a reservation to defend traditional uses of the coca leaf.
Updated until September 2012