Reporting from Ciudad Juarez, Mexico, and Mexico City -- In the baddest precinct of Mexico’s most violent city, Jose Manuel Resendiz is the law.

The army officer packs two pistols and a semiautomatic rifle as he patrols the Delicias district of Ciudad Juarez, the bullet-scarred border city that is the emblem of Mexico’s drug-war mayhem.

Riding in a Ford pickup with five gun-toting soldiers, he pulls over suspicious-looking cars, sets up impromptu roadblocks to search for drugs and weapons, and tends to the nuisance calls that make up a cop’s life: robberies, street fights, fender benders.

“I am an army lieutenant colonel,” Resendiz said. “But now we’re all police.”

Ciudad Juarez resembles a city under military occupation as President Felipe Calderon ratchets up his war against drug traffickers.

Calderon launched the military offensive 10 days after assuming office in December 2006, saying it was necessary to restore government authority in parts of the country. Today, 2 1/2 years later, Calderon and Mexico face a stark reality: The longer and harder the war is prosecuted, the more complex and daunting it becomes.

The offensive has exposed corruption so widespread that key institutions, from police forces to city halls, appear rotten to the core. And a battered society has grown increasingly worried about the effects of the massive military deployment on its democracy.

A cascade of setbacks -- prison breakouts, kidnappings of federal officials, killing of priests -- has led to questions about whether Calderon was prepared for the breadth and depth of the problem.

By disrupting the cartels’ operations, the offensive intensified turf struggles among the traffickers. About 11,000 people, some of them bystanders, have died in the violence.

“They hit a wasp nest, and the wasps are stinging,” said Jose Luis Pineyro, an expert on national security at Mexico City’s Autonomous Metropolitan University. “There definitely wasn’t a well-structured plan to know what kind of threat they were confronting.”

Government forces have scored victories, almost all credited to the military: They’ve arrested more than 66,000 suspects, seized tons of cocaine and marijuana, and intercepted guns, grenades, airplanes -- even drug-laden, submarine-like vessels.

But every success is offset quickly by a fresh surge in violence, sometimes in unexpected places such as the tourist magnet of Acapulco. No state has been spared bloodshed or scandal. To date, the government has not gone after major money-laundering operations, the fuel that keeps the cartels going, and none of the current leaders of the main cartels has been captured.

“It’s very hard to stop this trend,” a senior military official in Ciudad Juarez said, speaking of the unyielding bloodshed. “We are fighting an enemy we don’t know and don’t see and only feel their results.”

The drug gangs appear as strong and as vicious as ever as they fight not just for smuggling routes but for shares of the growing domestic market. Mexican cartels are now the dominant force in an industry once led by Colombians.

More than 45,000 troops have been deployed in these 2 1/2 years to hot spots across the nation. It’s not just boots on the ground: Army generals and colonels have taken command of law enforcement in seven states and, from Juarez to Tijuana to Cancun, have supplanted civilian authority.

Ciudad Juarez, a city of 1.3 million, remains the test case, embodying the reach of Calderon’s strategy and its risks. The military buildup in Juarez came after months of extraordinary violence. About 1,600 people were killed last year, including more than 200 in November alone.

In February, the police chief quit after several officers were shot dead and signs appeared threatening that more would be killed unless he stepped down. Other posters threatened the life of Mayor Jose Reyes Ferriz. The governor of the state, Chihuahua, was ambushed in the state capital. (He survived, but his bodyguard was killed.)

Juarez officials appealed for federal help, and in March, Calderon’s government sent 5,000 troops and 1,900 federal police officers -- adding to the 2,500 soldiers and police already there.

Reliance on army

A retired general, Julian Rivera Breton, was appointed public safety chief, and an active-duty colonel, Alfonso Cristobal Garcia Melgar, was installed as police director. In all, 30 current or former military officers now hold supervisory roles in the police department.

At the height of the violence, in February, there were 10 or more killings a day. The number has dropped to an average of four to eight a day, and bank robberies and car thefts are also down, authorities say. Still, the homicide rate for the first six months of 2009 is higher than it was last year, according to media tallies. Kidnapping and extortion remain rampant.

Hit men in Juarez, who used to ambush enemies with AK-47 and AR-15 assault rifles fired from fancy SUVs, have had to change their tactics. These days, most killings are done with pistols, and the getaway car is often a beat-up Honda. But the bloodshed goes on.

“The killings we’re seeing right now are young people that are trying to get started in a life of crime,” said Reyes, the mayor. “The whole change in the city has created circumstances that are much more favorable for us to get everything under control.”

The military presence in Juarez is striking. Police pickups and military trucks packed with troops are everywhere. Soldiers answer 911 calls, arrest drunken drivers and respond to shootings. Factory warehouses have been converted into makeshift encampments, full of colorful, store-bought dome tents.

In November, killers were able to break into the police radio frequency and play narcocorrido music as a sign an officer had been killed, or was about to be. Now, officials are developing a secure radio system.

Mistrust of police had been so high that residents were reluctant to call 911 out of fear that their names would be leaked to gangsters. Now, Reyes said, a hotline is being established to route calls to a center in an undisclosed Latin American country.

Graft-ridden police

Reyes said the military deployment is a temporary measure to give city officials time to clean up the police force. “We all knew there was police corruption,” he said, but “nobody knew how deep it was.” He plans to nearly double the size of the force, to 3,000 by the end of the year, and to use a strict vetting process.

Calderon’s administration says troops are likely to remain deployed throughout Mexico for the rest of his tenure, which ends in 2012, because it is believed it will take that long to purge and retrain the police.

“This fight is not viable without the army,” said Monte Alejandro Rubido, a senior security official in Calderon’s government. “What has surprised us is how quickly the business of street sales, and the violence from it, grew and spread, in areas where there had not been trouble from organized crime. Corruption and intimidation, that’s how they penetrated.”

Troops were dispatched in February this year to the northern border state of Nuevo Leon, Mexico’s wealthiest and long a symbol of relative stability. Traffickers quickly mobilized low-level dealers and their families to protest the military presence and to create the impression that the traffickers had a broad social base. Monterrey, the capital, and other cities were paralyzed for days.

Then the army started arresting police in Monterrey and other Nuevo Leon municipalities. In early June, troops backed by federal agents rounded up dozens of police officers and several commanders. When the police got wind of what was happening, they challenged the troops and tried to block roads.

As punishment, the federal authorities ordered the police to turn in their rifles. A day later, they confiscated their cellphones, suspecting the cops were using them to pass intelligence to traffickers.

A politician from the Monterrey area’s richest district was caught on tape describing the power of the drug lords. Mauricio Fernandez is heard saying that the area was relatively peaceful because the Beltran Leyva cartel wanted it that way.

“Their families live here,” he said. “You don’t think it’s the police [that maintain order], do you?”

In the central state of Zacatecas in May, prison guards were caught on videotape watching unperturbed as 53 traffickers, gunmen and other inmates casually walked out of a maximum-security jail.

In Calderon’s home state, Michoacan, army and federal agents swept into city halls and police stations in May, arresting 10 mayors and 17 other officials accused of aiding an especially violent cartel called La Familia (“The Family”). Traffickers in Michoacan, who specialize in methamphetamine, choose candidates for elections and force residents to pay tribute to the cartel rather than taxes.

The army’s role has expanded to such an extent that this month troops staged raids in the capital, Mexico City. Soldiers can enter homes and businesses without warrants and detain people without charges.

Critics worry that this could undermine the country’s fragile democracy. Others fear that the military, one of Mexico’s most respected institutions, will fall prey to the corruption that has corroded so many police departments. Ten army officers were arrested in June for allegedly passing information to fugitive drug lord Joaquin “El Chapo” Guzman.

Army abuses cited

Activists say soldiers trained for combat, not police work, have run amok at times.

Margarita Rosales, a laundry worker in Juarez, said her son, Javier, 21, was found dead in April after he and a friend were seized by soldiers and federal police after a night of drinking. His body bore marks of a severe beating, she said. Rosales said the friend told her that Javier, an X-ray technician, was singled out because he was heavily tattooed.

“He didn’t sell drugs. He wasn’t involved in that kind of thing,” she said. “If they had found kilos of drugs, kilos of cocaine -- but why? There is no reason why.”

Gustavo de la Rosa Hickerson, human rights ombudsman for the state of Chihuahua, said his office has received 200 complaints of abuse by the military, including allegations of suspects being tortured to extract information, wrongful detention and seven killings. Nationwide, complaints against the army tripled between 2007 and 2009.

Army officials say hitmen are dressing in military-style garb to abduct rivals. Soldiers in the Juarez area recently arrested 25 armed men, most of whom were wearing army-type uniforms.

Enrique Torres, spokesman for the joint military-civilian operation in Ciudad Juarez, said the government takes allegations of abuse seriously and will prosecute offenders in military courts. He said the army in Juarez was investigating 126 reports of abuse.

For all the improvements in Ciudad Juarez cited by the mayor, many residents are unconvinced that much has changed.

“There are still a lot of killings,” said Magda Duran, a 45-year-old factory worker. She stood on the porch of her home in the city’s ramshackle Delicias section as soldiers and police searched houses, including hers, for the victim of a reported kidnapping.

“They scare me,” Duran said of the troops. “They intimidate me.”

On this evening, a squad of 16 soldiers and police from Lt. Col. Resendiz’s precinct prowled in a pair of pickups past darkened beer joints and concrete shanties that hunker behind gates made of bedsprings and freight pallets. In grass-less yards, children grinned and waved. The soldiers waved back. Grown-ups stared, but none waved.

The rolling army patrol was summoned to a bleak neighborhood called Rancho Anapra. In the waning desert light, a man lay lifeless in the dusty street. He had been shot four times, in full view of a dozen houses.

Residents regarded the arriving troops with bored expressions, amid a cacophony of barking dogs.

There were many bystanders, but few witnesses. “Puro mirón,” grumbled a military police officer. “All just onlookers. We could ask them, but nobody will know anything. Nobody saw anything.”

The scene encapsulates one of the government’s biggest challenges in the drug war: overcoming the deep mistrust of ordinary Mexicans. “Only when something happens -- that’s when they come,” said one of the bystanders, Laura Valdivia, 36, who works in a factory that makes fake Christmas trees.

Other than his name, Daniel Chavez, and age, 35, no one seemed to have much to say about the victim, whose torso was a spider’s web of tattoos.

The crowd slowly evaporated. In darkness, the body was hauled away and the soldiers clambered back onto the pickups, knowing as little as when they arrived.

ken.ellingwood@latimes.com

wilkinson@latimes.com