Introduction: international drug policy in an era of growing complexity, challenge and tension

Varying patterns of stability and dynamism tend to characterize public policy across a range of domains. Drug policy, as an exemplar of a cross-cutting issue, is no exception. In many parts of the world, the last ten years or so have witnessed unprecedented – in some cases rapid in others more incremental – shifts away from the traditional law enforcement dominated approach to dealing with multiple facets of illegal drug markets. Elsewhere stasis, or even retrenchment, better characterizes the policy landscape. While impossible to neatly categorize such differences in approach, with many nations falling somewhere in-between, the growing mosaic of policy responses have to a greater or lesser extent been influenced by the increasingly complex and expanding nature of what has become known simply as the ‘world drug problem’. Reflecting a growing understanding of what by its very nature is a difficult market to quantify, the United Nations Office on Drugs and Crime (UNODC or Office) noted in the Preface to the 2019 World Drug Report , ‘The findings of this year’s’ flagship publication, ‘fill in and further complicate the global picture of drug challenges’ (UNODC, 2019, p. 1). The Report goes on to stress that in 2017 an estimated 271 million people, or 5.5 per cent of the global population aged 15–64, had used drugs in the previous year; a figure 30 per cent higher than in 2009 (UNODC, 2019, p. 7). Moving beyond simple prevalence figures, an issue discussed in detail at various points within this Research Handbook, UNODC also notes how an estimated 35 million people suffer from what it refers to as ‘drug use disorders’, with an estimated 585,000 people dying ‘as a result of drug use in 2017’ (UNODC, 2019, pp. 1 & 19). Within the context of these figures, as well, as among other things, fluctuations in drug crop cultivation, shifting and increasingly complex trafficking patterns (including in relation to illegal crypto-markets), the continued emergence of new psychoactive substances (NPS), a growing trend in the manufacture, trafficking and use of Amphetamine Type Stimulants in some parts of