In 1999, 31 members of the Mexican military special operations trained by US Navy Seals and members of the Israeli special forces abandoned their ranks within the Mexican military to join to the Gulf Cartel as force security agents for high-ranking cartel agents and as escorts for special drug trafficking expeditions. This was news to the Mexican military as in the 1980s and 1990s the Mexican government had a generally laissez faire approach to cartels. Basically, if the cartel wasn't attacking the government and wasn't blatantly clear about its operations, then the government wouldn't do much about it. When the power of the Institutional Revolutionary Party (PRI) waned in the late 1990s, high-ranking members of the Gulf Cartel saw that this period of non-intervention policy towards organized crime was ending and made a move by convincing these 31 men to join as a security force. known then as Zetas (Frontier Land). Led by members known as Z-1 and Z-2, Heriberto Lazcano Lazcano and Jaime Gonzalez Duran changed the face of Mexican crime forever. The Zetas were then known for their brutality in dealing with citizens and rival cartels who refused to cooperate with the Gulf Cartel. As the government began cracking down on crime, the Zetas continued to become more violent, recruiting more military members and subjecting them to self-training. As the Zetas grew and rose higher in the Gulf Cartel, there was a lot of animosity. Gulf Cartel members were reluctant to let these new members into the top ranks of the organization. This led the Zetas to push harder in their dealings and eventually split from the cartel entirely to form the independent Los Zetas cartel in 2010. The Zetas now have over 3000 members and most of them have... half the paper . .....leader for as many years. A high turnover of high-ranking officials can lead to divisions within the ranks and a division of power, diminishing their influence over Mexico. That may be Mexico's intent here, just trying to capture high-ranking officials, in an attempt to cause mass chaos while allowing the military to regain some control. As mentioned above, the Zetas are famous for their brutality and ferocious attacks. Most of these arrived in the last 5 years while they were at war with rival cartels, the Sinaloas and Gulf cartels. In August 2010, Los Zetas were involved in the San Fernando massacre, executing 72 immigrants allegedly recruited by the Gulf Cartel. This however was only part of the massacre, as 8 months later San Fernando witnessed another brutal attack: 193 people were taken from buses heading to Gulf border towns and executed..