Osiel Cárdenas Guillén, the former leader of Mexico's Gulf Cartel and founder of the Zetas, has been released from a U.S. prison after serving most of his 25-year sentence. He is now in the custody of U.S. Immigration and Customs Enforcement and faces potential deportation to Mexico, where he has pending charges. Cárdenas Guillén, infamous for his brutal tactics and establishment of the Zetas as a paramilitary wing, is blamed for initiating an era of extreme violence in Mexico. Speculation abounds regarding his future, with some expecting his return to the cartel's activities, while others suggest he may remain under U.S. protection. His release has reignited fears of increased cartel violence as factions vie for control. The Zetas, initially formed as his private army, later became an independent and deadly force in Mexico's criminal landscape.