The killing of the Mexican cartel boss known as 'El Mencho' has unleased a power struggle in the criminal underworld. Among the rival groups hoping to gain influence is the Jalisco New Generation cartel - one of Mexico's most violent and notorious organizations. The group is behind the trafficking of cocaine, amphetamines, and fentanyl to the United States - and is feared for its ruthlessness. We spoke to Vanda Felbab-Brown, Director of the Initiative on Non-state Armed Actors at Brookings in