In 1998 the UN General Assembly Special Session on the World Drug Problem (UNGASS) met to announce ongoing support for the international drug control regime. For the last hundred years this has privileged punitive-prohibition over other approaches. Today, however, as David Bewley-Taylor of Swansea University explains, diverging views on the non-medical and non-scientific use of controlled substances make drug policy an increasingly contested and transitionary field of multinational cooperation.