Gulf Cartel
It is unclear which of the twothe Gulf Cartel or Los Zetasstarted the conflict that led to their break up. It is clear, however, that after the capture and extradition of Osiel Cárdenas Guillén, Los Zetas outclassed the Gulf Cartel in revenue, membership, and influence. Some sources reveal that as a result of the supremacy of Los Zetas, the Gulf Cartel felt threatened by the growing force of their enforcer group and decided to curtail their influence, but eventually failed in their attempt, instigating a war. According to "narco-banners" left by the Gulf Cartel in Matamoros, Tamaulipas, and Reynosa, Tamaulipas, the reason for their rupture was that Los Zetas had expanded their operations to include extortion, kidnapping, assassinations, theft, and other actions with which it disagreed. Unwilling to stand for such abuse, Los Zetas responded and countered the accusations by posting their own banners throughout Tamaulipas. They pointedly noted that they had carried out executions and kidnappings under orders of the Gulf Cartel when they served as their enforcers, and they were created by them for that sole purpose. Also, Los Zetas mentioned that the Gulf Cartel also kills innocent civilians, and then blames them for their atrocities.