Los Zetas represent a new generation of ruthless, sadistic pragmatists in Mexico and Central America who are impelling a tectonic shift among drug trafficking organizations in the Americas. Mexico's marines have taken down the cartel's top leaders; nevertheless, these capos and their desperados have forever altered how criminal business is conducted in the Western Hemisphere. This narrative brings an unprecedented level of detail in describing how Los Zetas became Mexico's most diabolical criminal organization before suffering severe losses.

In their heyday, Los...