Residents of La Ruana cheered as Mexican army soldiers enter the town to help defend them against a drug cartel, relieving a growing vigilante movement made up of farmers and shopkeepers. (Marco Ugarte/Associated Press)

Villagers in Mexico’s troubled western state of Michoacan lined the highways this week to cheer the arrival of soldiers sent by President Enrique Peña Nieto to reoccupy their towns. But the scenes have underscored the seeming intractability of the country’s security problems.

Peña Nieto’s predecessor, Felipe Calderón, launched an offensive against Mexico’s drug cartels in 2006, at the outset of his term, by ordering thousands of troops into the same state, at the time in the grips of a vicious trafficking syndicate known as La Familia.

Six years later, the Mexican government and its U.S. advisers have all but wiped out La Familia. But as federal forces receded, an equally powerful cartel, the Knights Templar, took its place, squeezing extortion payments from entire towns, torching businesses and killing anyone who challenged its rule.

Local farmers and shopkeepers have increasingly banded together to form armed “self-defense” groups, chasing off corrupt cops and setting up checkpoints along the highways to sniff out traffickers.

But their appearance in more and more towns — and the spectacle of masked, ragged irregulars parading around on national television with weapons — has presented a growing challenge to the Peña Nieto government, sensitive to the perception that the Mexican state is teetering in parts of the country.

The self-defense groups have also brought the wrath of the gangsters, who have shot up their towns and laid siege by cutting off shipments of gasoline, food and other supplies. In some parts of Michoacan, the charred hulks of delivery trucks line roadways, left as warnings to businesses that might try to defy the cartel cordon.

With the towns appealing to the government for help, the Peña
Nieto administration is launching yet another attempt to placate Michoacan’s Tierra Caliente, or “Hot Land,” a farming region along the Pacific Coast that was famous for its avocados and melons before it earned a reputation for meth labs and beheadings.

On Tuesday, Mexico’s top security officials convened amid heavy security in Morelia, Michoacan’s capital and a city that used to be popular with U.S. students but is now a virtual no-go zone for foreign tourists.

Mexican Interior Secretary Miguel Osorio Chong told reporters after the meeting that federal forces would not pull back from the state until law and order had been restored.

“Our fundamental goal is simple: to come to Michoacan and not leave until peace and security have been provided for every Michoacan resident,” he said.

Osorio Chong pledged smoother coordination among local, state and federal forces this time, led by the military commander that the Peña Nieto administration has placed in charge of security for the state. He said the government has had little trouble getting the vigilante groups to stand down so far, because “they have been asking for a military presence.”

When the military convoy rolled into the town of La Ruana on Monday to cheering crowds, the ragtag local self-defense force that had been staving off the Knights Templar declared victory.

“After three months of fighting, we can sleep peacefully in our homes,” Hipólito Mora, La Ruana’s militia leader, told the town, according to Mexico’s Reforma newspaper.

But villagers there and in other nearby towns said they would not give up their weapons, lest the troops depart and leave them vulnerable again.

While many of the vigilante groups that have arisen here and elsewhere in Mexico appear to be authentic self-defense patrols — armed with old hunting rifles, shotguns, sticks and machetes — the sight of uniformed militiamen brandishing AK-47s and other powerful weapons in some parts of Michoacan had raised suspicions that they are front groups for the Knights Templar or other cartels.

“In these poor communities, people can’t afford assault rifles and brand-new pickup trucks,” said Raúl Benítez, a security expert at Mexico’s National Autonomous University.

Benítez said that if Peña Nieto’s troop deployment in Michoacan looks similar to the Calderón plan, it’s because the new administration is still far from being able to implement the “violence reduction” strategies it claims to favor, emphasizing economic development, social programs and law enforcement work over military force.

With the state of Michoacan slipping out of control and the militia movement spreading, “Peña Nieto is using the only thing he has — the military,” Benítez said.

That, too, seemed to be Calderón’s only option when he set out to crush La Familia. By the end of his term, he was touting his government’s victories against the gang as one of his hallmark security achievements, particularly after Mexican troops claimed to have killed the cartel’s leader, Nazario Moreno, nicknamed “The Craziest One,” during a two-day gun battle in 2010.

But as La Familia broke up, it sprouted new spinoffs such as the Knights Templar, which seized control of its old trafficking business and extortion rackets.

“This new military deployment shows us that Calderón’s success wasn’t real,” said Martin Barron Cruz, a researcher at Mexico’s National Institute of Criminal Sciences. “The criminals have come back even stronger than before.”