Editor’s Note: In July 2019, this story received an Honorable Mention by the National Press Club for the Edwin M. Hood Award for Diplomatic Correspondence, which recognizes excellence in reporting on diplomatic and foreign policy issues.

For 15 years, El Salvador’s zero-tolerance approach to gangs—known as mano dura, or iron fist—has resulted in devastating violence while failing to address the root causes of the crimes it’s supposed to eliminate. Yet this approach to dealing with gangs in El Salvador remains a favorite of politicians, and it has a new backer in the Trump administration. ...