Tijuana – The city has been divided into two parts by two drug cartels, which besides unleashing their relentless violence have laid bare enduring social problems of the border.

This fragmentation could worsen as other criminal groups arrive to take advantage of the weakened state of the organization that historically controlled Tijuana, experts warn.

One part is the city's east side, controlled by the Sinaloa cartel. Though it's home to the maquiladora industry, many residents who live in the area's crowded colonias lack public services and lead lives of hardship.

The other part is the western side, dominated by the Arellano Felix cartel, which historically had controlled drug trafficking in the city.

However, authorities have detained members of a cartel from the state of Michoacán, known as La Familia, which has used a Tijuana route to cross its drug shipments into the United States, apparently paying a "rental fee" to the Arellanos, authorities said.

Experts question how long these arrangements will last, particularly given the fluid nature of the drug trade. And particularly after the apprehension of bands of criminals working for the cartels. These have come after anonymous tipsters alerted authorities to drug shipments and safe houses, where kidnapping victims were being held and weapons stored.

Just in the last two weeks, Mexico's Defense Department and state authorities announced the arrest in Tijuana of criminal cells working for these three drug cartels.

In a Jan. 9 operation, Rigoberto Andrade, nicknamed El Rigo, was apprehended. Mexican military officials identified him as a leader in the La Familia organization, and as the brother of Ignacio Andrade El Cenizo, a lieutenant in the cartel.

Four days earlier, the Mexican Army and municipal police captured Jesús Israel Cruz López, El Tomate, the leader of a cell working for the Sinaloa cartel. He had inherited the criminal organization after its leader, Teodoro García Simental, was arrested in January of 2010.

The director of Public Administration Studies at the think tank Colegio de la Frontera Norte, José María Ramos, explained that various criminal groups are attempting to establish themselves in this region to control the drug market.

"They are taking advantage of the weakening of the criminal group that traditionally had controlled of the (drug) corridor," said Ramos.

He added that despite the important work being done by authorities, particularly by the Mexican Army, until U.S. officials do more to reduce the demand for illegal drugs, in other words, institute effective anti-drug public policies, the fundamental problem will continue.

For social anthropologist Victor Clark, who has studied drug trafficking for more than two decades, the arrival of new cartels in this city dates back 11 years, although the process has stepped up in the last three.

"The Arellano cartel had its peak in the 1990s, but by the new millennium had begun to face difficulties, particularly after the apprehension of its historic leaders and the death of one of them (Ramón Arellano)," he said. "All that led to signs of weakness and a reduction in the territories they had controlled a long time."

The Arellano's cartel was also known as the Pacific cartel because it controlled the Mexican states along the Pacific Ocean. Currently, the group has practically reduced its activities to Tijuana, although it has a presence in the United States and other countries.

"Their historic enemies have taken advantage of the group's decline over the years, particularly the Sinaloa cartel," he said.

Today, the Sinaloa cartel has a significant presence in Baja California, controlling the Mexicali and San Luis Río Colorado routes toward the United States – and Tijuana's east zone, he said.

The cartel La Familia of Michoacán has apparently paid a "renter's fee" to the Arellanos to use its route to cross drugs into the United States, Clark said. This cartel has a minority presence in Rosarito Beach, basically to move drugs through the area, but the zone remains in Arellano hands.

Officially, the war between the Arellano and Sinaloa cartels led to 2,325 deaths in Tijuana from 2008 to 2010, as well as the disappearance of 390 people.

This clash also divided the city, since for the most part it was fought in the east side, where nearly 1 million of the Tijuana's 1.6 million people live.

"These two criminal groups divided the city, they distributed it among themselves," Clark said.

Social researcher Ramos sees the division not so much as the result of the cartels' violence rather as a consequence of a chronic social problem of the border.

Hundreds of maquiladoras began operations in the east side in the boom years of the 1980s and 1990s, attracting thousands of Mexicans from elsewhere in the country looking for better job opportunities or who planned to immigrate to the United States.

Many of them stayed to live in the hillsides and canyon of that area, which did not have public services nor schools.

This situation, he said, has led to the marginalization of its residents which in turn produced conditions ripe for an increase in crime, particularly among teens and young adults who are directly or indirectly connected to street-level drug dealing.

"As long as public policies do not address this situation … above all with prevention programs, crime will continue to increase," he said. "It's a vicious circle."

Various state and municipal administrations have promised public policies to improve the life on the east side, but the educational and preventive programs have always been temporary, inadequate or changed from one government to the next.

As a result, civic and non-profit groups are taking the initiative creating diverse cultural, artistic, sports and social projects to begin to address the community needs.

Ramos pointed out that what is occurring Tijuana is also happening in other border cities wracked by drug violence.

Ciudad Juárez, Nuevo Laredo and Nogales all grew rapidly in the last 15 years due to the boom in the maquiladora industry, but the socioeconomic condition of their residents, particularly those living poor neighborhoods, did not improve.

omar.millan@sandiegored.com