US President Richard Nixon declared illegal drugs 'public enemy number one' in 1971 and launched a worldwide 'war' on the narcotics trade. 50 years on we revisit key moments in the ongoing fight against the powerful criminal groups involved from Columbia to Afghanistan. We'll hear personal stories from the front line of drug addiction, plus journalist and author Ioan Grillo joins our presenter Max Pearson to discuss, what went wrong in the war on drugs?

Photo: US President Richard Nixon (BBC)