This book provides the first comprehensive, critical analysis of the drugs problem in Ireland over the last thirty years with a particular focus on the role of drugs in crime and the role of prohibition in generating drug-related harms. Using Ireland's disastrous history of prohibition and the failure of its well-resourced harm reduction programme as a case study, the book goes on to challenge the global dominance of prohibitionist ideology, which is seen as an emotionally driven and fundamentally irrational belief system, which flies in the face of overwhelming evidence that prohibition does more harm than good. Prohibition's defences against the mass of evidence demonstrating its detrimental effects and ultimate futility are one by one exposed and dismantled. The book argues that international and national law should be based on a realistic appraisal of human nature and that a scientific view of human psychology and of the human condition explains not only the value and irresistible attraction of mood-altering substances, but also the young's stubborn resistance to the prohibitionist message. The book argues that society would make substantial gains from accepting the libertarian view that there is a right to use drugs so long as others' rights are not infringed. A non-coercive harm reduction approach based on the right to use drugs could have major benefits, eliminating many of the ill-effects of prohibition and creating a positive attitudinal dynamic that lowers the irresponsible and destructive use of drugs.