Who he is: President Enrique Pena Nieto, 46, is a lawyer who served as governor of Mexico state. He begins his term on a politically shaky foundation. He won 38 percent of the vote in July and his opponents allege irregularities in the voting.

Drug fighting: He has vowed to continue efforts to work with U.S. law enforcement agencies to quell the violence linked to drug gangs. The violence has killed tens of thousands in the past several years.

Economy: His administration plans more steps to stimulate the economy, arguing that generating better-paying jobs will go a long way toward reducing violence by providing alternatives to crime for the chronically underemployed. Mexico's economy rebounded from a recession in 2009 and is growing faster than that of the United States with an infusion of manufacturing plants and other investment.

Security: The president plans to reorganize federal security forces and intends to form paramilitary units with police duties to combat violence in rural areas and support local and state police departments that are too corrupt or poorly trained to fight crime.