Just read this after my comment. You are ABSOLUTELY correct. What you see is some warring within that is political anything else is smoke and mirrors.
Folks know what happens to countries the US deems to contain terrorists.
Obrador's excuse was that he feared that officially recognizing los Zetas as a terrorist organization would tarnish Mexico's reputation. This alleged fear of the US only fits if they feared an outsider intervened to put a stop to the mafia's dominance.