NEW WEB OF TRUST TOPPLES A MIGHTY MEXICAN CARTEL

By TIM WEINER

TIJUANA, Mexico - Last summer, Benjamin Arellano Felix, chief of the
multibillion-dollar cocaine cartel that bears his name, was drinking
tequila with senior Mexican police officials long in his pay.

That party is over. Mexico has jailed Mr. Arellano Felix and many of his
top confederates, who wielded more power and influence in the drug trade
from Mexico into the United States than any other group.

Bringing down the Arellano Felix dons was the biggest victory in years in a
bloody drug war Mexico had seemed certain to lose. The arrests capped a
string of successes that also nabbed top dealers from all the major Mexican
syndicates.

For President Vicente Fox, Mexico's first fully democratic leader,
defeating the Arellano Felix clan was an important victory. He campaigned
in 2000 claiming that if he ousted the entrenched authoritarian system, he
would curb some of the corruption it fostered.

The progress, American and Mexican officials said, stemmed from renewed
cooperation between Mexico and the United States in the hunt for cartel
leaders. Agents on both sides rebuilt trust that had been eroded by Mexican
officials in the drug gangs' pay.

The attack on the Arellano Felix family was spurred by Mexican-American
investigators and prosecutors based just across the border in San Diego.
American agents succeeded in piecing together a picture of the cartel's
cash flow and hideouts from "informants, witnesses, financial information,"
said Errol Chavez, chief of the Drug Enforcement Administration's San Diego
office.

That picture provided "a much higher level of intelligence to the Mexicans
than ever before," Mr. Chavez said. Last month, the agents tracked cartel
couriers carrying cash over the border from California. One group of bag
men went from San Diego to Tijuana, to Mexico City, and then to a modern
house in the city of Puebla.

After weeks of surveillance, a squad of Mexican army antidrug commandos
broke down the door on March 9. They found Benjamin Arellano Felix inside.

Mexican and American officials expect their cooperation to yield new
arrests. Mr. Fox, who once said the military should be removed from the
drug war, has particularly praised the armed forces for their recent role.
The drug triumphs have also strengthened Mexico's attorney general, Rafael
Macedo de la Concha, who has been controversial as head of the justice
system because he is himself a former army officer.

The Arellano Felix gang, based in Tijuana and led by Benjamin and his
baby-faced brother, Ramon, is accused of killing hundreds of people. In
1999, the head of the D.E.A., Thomas Constantine, said the gang was "immune
to any law enforcement efforts."

Don Thornhill, a D.E.A. agent who fought the cartel, said: "We had so many
cases compromised, the corruption was so deep, you got to the point of
asking yourself, 'Why pass information on? I'm going to get a source killed.' "

Things began to change in November 1999 with a series of secret meetings
between the Americans and the Mexicans. The Americans included Mr. Chavez
from the D.E.A., along with Gregory Vega, then the new United States
Attorney in San Diego, and his chief drug prosecutor, Gonzalo Curiel. The
Mexican side included Jorge Madrazo, then the attorney general, and two top
drug prosecutors, Jose Patino, known as Pepe, and Jose Vasconcelos.

According to participants on both sides, the Mexicans looked across the
table at Mr. Chavez, Mr. Vega and Mr. Curiel, all born of Mexican parents,
and the spark of recognition lit a fire.

"It couldn't but help," Mr. Curiel said. "We were working without the
disconnect of interpreters and barriers of culture. When it comes down to
it, this involves the country of our parents." Mr. Vega, now in private
practice, said the simple fact that the meetings were conducted in Spanish
"broke the ice."

"It was confianza," he said, the Spanish word for trust.

After the November 1999 meeting, the United States, in one last try at
building a professional Mexican antidrug force, sharply increased the money
it provided to train Mexican law enforcement personnel. It has tripled to
$12 million this year.

"If you have good investigators, you'll have good investigations," Mr.
Vasconcelos, now chief of Mexico's new organized-crime task force, said in
an interview.

The soldiers and investigators on Mr. Vasconcelos's year-old force are
vigorously vetted and isolated from their fellow officers, to prevent
illegal influences. "This has decreased corruption," he said

But cocaine-fueled corruption still ran rampant in Tijuana and the
surrounding state of Baja California.

In February 2000, President Ernesto Zedillo went to Tijuana to issue a new
declaration of war on crime. The cartel's answer came two days later with
the assassination of the city's police chief.

The law struck back three weeks later with the arrest of Jesus Labra
Aviles, the gang's financial strategist, as he was watching a soccer match
in a Tijuana stadium.

Again, the cartel counterattacked. In April 2000, Mr. Patino, the Mexican
investigator most trusted by his American counterparts, was kidnapped and
killed, as were two aides.

Mr. Patino was killed as he was crossing back into Mexico from a D.E.A.
safe house in San Diego. Only a handful of Mexican officials knew the time
and place of his crossing. One of them, Cesar Jimenez, a member of the
attorney general's antinarcotics task force, became a fugitive.

"At that point, everything became focused on the Arellanos," Mr. Curiel
said. "It may have taken the death of Pepe Patino and his two colleagues to
jump-start it."

The investigation "began to click into place," said Mr. Chavez, after Mr.
Fox became president in December 2000. Days after taking office, Mr. Fox
went to Tijuana and pledged to cleanse the city of corruption in a matter
of months. Few believed him.

But "the Fox administration was able to fire corrupt officials, replace
many others, and develop a strategy to attack the Arellano Felix
organization," Mr. Curiel said.

During the past year, 10 suspected Arellano Felix cartel members have been
arrested in Mexico, among them Ramon's favorite assassin, Jorge Humberto
Rodriguez, known as La Rana, the frog.

But no arrest proved more important than that of Ivonne Soto Vega. She
owned luxurious houses and a network of legitimate-looking
currency-exchange businesses on both sides of the border. She was arrested
in July 2001 and charged as the cartel's chief money-launderer. Her arrest
helped investigators understand how the Arellanos' profits flowed south.

Cartels like the Arellano Felix gang, after selling their drugs in the
United States, usually wired the proceeds to cooperative Mexican banks.
Bankers, happy to take a 1 or 2 percent commission on huge sums, issued
dollar-denominated bank drafts, good as gold in any country.

But the Arellanos, agents discovered, also had a small army of couriers
based in and around Los Angeles and San Diego, where the cartel controlled
street gangs in charge of the retail end of the operation. The couriers
would ferry the money back across the border, officials said.

Tracking those couriers, the investigators were finally led to Benjamin
Arellano Felix.

The government also had some unexpected help from a drug rival of the
Arellano Felix gang. According to American investigators, Ismael Zambada,
known as "El Mayo," hoped to corner a larger part of the drug flow through
northwestern Mexico. Working with corrupt state police officers in the
resort town of Mazatlan, he ambushed and murdered Ramon Arellano Felix, the
gang's enforcer, on Feb. 10.

"Looking back, I am struck by the cumulative effect," Mr. Curiel said. "The
trusted assassins the Arellanos had, like La Rana, are gone. The money
launderers, taken out. There's been so much corrosion, so much dismantling
of the network, that by the time Benjamin goes down, much of the structure
is gone."

Still, Mexico has a long way to go before it unravels the system of
impunity and law enforcement protection that supported the cartel. This
month, 41 senior law enforcement officers, including the Tijuana police
chief, were detained on charges of taking bribes from the Arellano Felix
gang. But federal authorities have charged only nine of the men and have
set the rest free.