United Nations classifies the coca leaf as a narcotic and imposes a blanket prohibition on drugs.  Successive governments in Bolivia, the world's third-biggest producer of coca leaf and cocaine, have long tried to give the ancient leaf a new and improved reputation without success.  However, in a surprise decision last fall, the World Health Organization announced it would launch a landmark study of the coca leaf's non-narcotic benefits—the first step in the lengthy process to decriminalize the leaf worldwide. (AP Video shot by Carlos Guerrero)