A look at key events in Mexico's war on drugs following the extradition of drug lord Joaquin "El Chapo" Guzman.
— Dec. 11, 2006: Then-President Felipe Calderon orders almost 7,000 soldiers to his home state of Michoacan to fight drug cartels.
— June 30, 2008: U.S. announces $1.6 billion in anti-drug aid for Mexico under the Merida Initiative.
— Jan. 31, 2008: A gang bursts into a party and kills 16 young people in Ciudad Juarez, across the border from El Paso, Texas. The victims' relatives yell at Calderon.
— Aug. 23, 2010: The bodies of 72 migrants killed by the Zetas drug gang are found in San Fernando, Tamaulipas...