What happens when one parent takes a child across international borders without the other parent’s permission? In 1980, the United States and international partners created a treaty that lays out the rules for what federal officials are supposed to do in such cases. Judges are instructed to send children back to their home countries – with very few exceptions. Lawmakers imagined the treaty would usually help left-behind mothers, trying to get their children back from abductor-fathers. Today, more than a quarter of a century after the U.S. implemented the treaty, the standard profiles of abductor and left-behind-parent have shifted dramatically. The majority of the taking parents – the abductors – are women. And most of those women are victims of domestic violence, fleeing their abusers with their children.

When violent crime goes up, we usually hear about law enforcement responses. More police on the streets. More jails. Harsher penalties. But Chicago, and other cities around the world, is also trying an unlikely cure for violence:…