The last decades, changing societal phenomena concerning the drug problem influenced the national strategies and legal approaches of countries in a significant manner. Indeed, many European and other countries have developed a differentiated, multidisciplinary national drug policy.The pursuance of risk reduction strategies and the possible depenalisation of acts related to personal consumption remain controversial topics, though implemented in several countries. This book gives an overview of the main relevant international legal instruments dealing with the control of the drug problem.The United Nations, as well as the Council of Europe and the European Union have established an international legal framework to tackle the problem of illicit substances. The reader will find the full texts of the three United Nations drug Convention in annex of this book. On the one hand, the book provides an analysis of the latitude that Parties have within the present United Nations Conventions to dev