So here’s my proposal. First, we must address the violence and despair that are pushing migrants out of these three countries.

The good news is we already know how to reduce violence and corruption, and strengthen good government. In Honduras, the United States has been running pilot violence prevention programs since 2014. In neighborhoods like Rivera Hernández in San Pedro Sula we have funded outreach centers where children can find mentors and help getting jobs, cutting off the gangs’ lifeblood: new recruits. We put children most at risk of joining gangs in family counseling. And most important, we went after killers.

In 96 percent of homicides in Honduras in recent years, no one was convicted. Witnesses know: you testify, and the gang kills you immediately. The United States helped fund a nonprofit, the Association for a More Just Society, to investigate all murders in the most violent neighborhoods. It persuades witnesses to testify, anonymously, covered in a black burqa. In Rivera Hernández, murders plummeted by 62 percent in two years. And the number of Honduran children showing up at the United States border was cut almost in half.