"This report examines the causes for the escalation of the violence in Mexico. It provides a brief overview of Mexico's counterdrug efforts, a description of the major DTOs, the causes and trends in the violence, the Calderón government's efforts to crackdown on the DTOs, and the objectives and implementation of the Mérida Initiative and other measures the U.S. government has taken to support Mexico in its battle with the drug traffickers." According to the report, "drug-related violence in Mexico has spiked in recent years as drug trafficking organizations (DTOs) have competed for control of smuggling routes into the United States. Drug trafficking issues are prominent in Mexico because the country has for at least four decades been among the most important producers and suppliers of heroin, marijuana and (later) methamphetamine to the U.S. market. Today it is the leading source of all three drugs and is now the leading transit country for cocaine coming from South America to the United States. Although previous Mexican governments had accommodated some drug trafficking in the country, when President Felipe Calderón came into office in December 2006 he made battling the Mexican drug trafficking organizations a top priority. He has raised spending on security and sent thousands of troops and federal police to combat the DTOs in states along the U.S.-Mexico border and throughout the country. In response to the government's crackdown, the DTOs have responded with escalating violence."
CRS Report for Congress, R40582