By Tina Rosenberg
This is a story about a courageous policy in an unexpected place. In this place homeless shelters have vending machines selling clean syringes for injecting drugs. Drug users are not prosecuted as long as they are in treatment programs. Drug addicts are given clean needles and methadone maintenance therapy ─ available on a widespread basis even in prison. These tactics have worked to reduce crime, lower H.I.V. rates among drug users and keep AIDS from spreading out into the general population. The place is not Amsterdam. It is Tehran.