Mexico’s battles with drug trafficking have been a constant in the country’s modern history, but the activities and organization of the criminal groups operating in the clandestine industry have been in a state of constant flux. That flux, which continues today, lies at the heart of Mexico's violence.

Juarez has always been a volatile place. It is a border city that draws huge numbers of migrants seeking work, and engenders large discrepancies between its wealthiest and poorest residents -- all factors associated with violence.

There appears to have been a security miracle in Ciudad Juarez, once one of the world's most violent cities. But while some applaud the city’s police chief, Julian Leyzaola, others fret about his near-systematic violation of human rights.

Barrio Azteca, a prison gang born in the Texas jail system, is becoming a major player in the Mexican underworld and the "X-factor" in the battle for Ciudad Juarez, Mexican officials told InSight Crime.

For many crime watchers, the fighting in Juarez that cost nearly 10,000 people their lives over a four year stretch was a battle of the titans: the Juarez Cartel versus the Sinaloa Cartel. But beneath that analysis is the deeper question of who pushes the levers of power in Mexico.

Mexican officials have announced plans to send army troops and federal police to patrol roads in a mountainous region of border state Chihuahua, as part of the new administration’s strategy to combat organized crime and violence.

Ciudad Juarez, once one of Mexico's most notorious and violent cities, saw its homicide rate drop over 60 percent between 2011 and 2012, a decrease which may have more to do with organized crime dynamics than security policy. 

Juarez City police chief Julian Leyzaola replaced a top security aide considered one of his most trusted confidants, although he said the decision had nothing to do with a recent surge in violence that left three police officers dead the past week. 

The DEA has released the results of a two-year-long investigation into the international connections of Mexico's Sinaloa Cartel and Juarez Cartel, which it says resulted in nearly 4,000 arrests and the seizure of six tons of cocaine, among other drugs. 

A Southern Pulse report on Ciudad Juarez provides a glimpse at the dominant forces behind organized crime in the border city, once the “ground zero” of Mexico’s drug war, and offers a cautiously optimistic outlook for the future.