Editor's Note: This Security Weekly assesses the most significant cartel-related developments of the first quarter of 2013 and provides updated profiles of Mexico's powerful criminal cartels, as well as a forecast for the rest of this year. It's the executive summary of a more detailed report available to clients of our Mexico Security Monitor service. Balkanization of Cartels Since the late 1980s demise of the Guadalajara cartel, which controlled drug trade routes into the United States through most of Mexico, Mexican cartels have followed a trend of fracturing into more geographically compact, regional crime networks. This trend, which we are referring to as "Balkanization," has continued for more than two decades and has impacted all of the major cartel groups in Mexico. Indeed the Sinaloa Federation lost significant assets when the organizations run by Beltran Leyva and Ignacio Coronel split away from it.