Despite decades of battling against narcotics, the levels of addiction, trafficking and violence continue to rise. The war on drugs has failed. Now, politicians in Latin America are calling to review all options – from full legalisation to a new war

Four decades ago, on 17 July 1971, President Richard Nixon declared what has come to be called the "war on drugs". Nixon told Congress that drug addiction had "assumed the dimensions of a national emergency", and asked Capitol Hill for an initial $84m (£52m) for "emergency measures".