MEXICO CITY — The corpses of the 12 police officers were laid out along the mountain highway in a neat line, the cuts and burns of torture scarring their torsos and bullets embedded in their brains.

Surrounding the carnage were three notes bearing the same message in scrawled handwriting: “Try and arrest another one of us. We are waiting for you here.”

The mass killing of the federal agents, who had been abducted while off duty, happened at the peak of a rampant offensive by a Western Mexico drug cartel against government forces over the last week.

The operation — one of the cartels' boldest coordinated campaigns in recent history, undermining President Felipe Calderon's efforts to crack down on the cartels — included attacks on more than 16 police bases with grenades and automatic rifles, the torching of dozens of squad cars and ambushes that killed at least four more officers.

One local journalist, Ciro Gomez Leyva of the newspaper Milenio, likened it to the Vietnam War's pivotal "Tet Offensive," which brought the Viet Cong and North Vietnamese troops into open combat with the forces of the South Vietnamese army and its U.S. allies.

“It is that kind of Hollywood-style, synchronized action ... that created the perception that the once invincible army of Washington could never win in Vietnam,” Leyva wrote.

Any comparison to the storied Vietnamese campaign on Tet (the lunar new year) may well be overstated, as Mexico’s drug cartels have stuck to their guerrilla-style hit-and-run tactics rather than mounting military-standard attacks.

As the government sent in an extra 5,500 federal police and soldiers to the region of the attacks on Friday, the cartel seemed to melt back into its barrios and mountain villages, creating a pause in fighting.

But while it may not have amounted to a conquest of territory for the drug gangs, the offensive certainly has all but shattered public confidence in the government’s efforts to bring the cartels to heel.

Only 28 percent of participants in a survey undertaken this week, during the attacks, believed that the government was winning its war against drug gangs, while 51 percent said the gangsters were winning. In the poll, taken by the Cabinet for Strategic Communications, another 21 percent said that neither side was winning,

The assaults also struck a painful blow to the morale of the federal police officers on the front line of the drug war.

“This is a very difficult time for us. Most of us are family men and we wonder if our jobs are really worth this much risk,” said a federal agent, who asked his name not be used in fear that such negative statements would be scolded by his commanders.

Since Calderon began his war on drug cartels in December 2006, more than 1,000 police and soldiers have been killed. There have been more than 12,000 drug-related slayings in that period.

The latest attacks were particularly demoralizing for Calderon as they all occurred in his home state of Michoacan — where he launched his crack down.

A lush mountainous region that touches the Pacific coast, Michoacan has long been a center of marijuana and opium cultivation.

In more recent years, its remote peaks have also spawned dozens of labs churning out crystal meth, the highly-addictive synthetic drug whose popularity has spread quickly in the United States.

This valuable drug-producing territory spawned a sinister and extremely violent cartel known as La Familia Michoacana, which claims thousands of members in the state.

In 2006, when Calderon was running for the presidency, La Familia hacked the heads off five rival drug traffickers and rolled them across a disco dance floor.

In his very first days in office, the new president ordered 6,500 soldiers and police into Michoacan with the stated aim of bringing peace back to the region.

For a time, he seemed like he may have been able to claim his tactic was working, with the number of killings going down in Michoacan, even as they spiked elsewhere in Mexico.

But the latest offensive shattered any such hopes.

The attacks were triggered by the July 11 arrest of Arnoldo Rueda, an alleged capo in La Familia, who was snatched from his family home in a dawn raid.

Within hours, about 40 gunmen had descended on the police headquarters where he was taken and attacked it with grenades and rifle fire in an attempt to free their leader.

When they couldn’t bust him out, they waged simultaneous attacks on police facilities in towns all over the state.

Following days of devastation, a man claiming to be La Familia capo Servando Gomez then called a Michoacan television station offering a truce.

“What we want is peace and tranquility,” he said to a worried-looking presenter. “We want to achieve a national pact.”

Interior Minister Fernando Gomez Mont immediately rejected the offer, saying the government will not bow to criminals.

“The federal government does not ever dialogue, does not negotiate, does not reach deals with any criminal organization,” he said.

But whether Calderon will really sustain such a concerted assault on the cartels for three more years in office remains to be seen.

More GlobalPost dispatches on the Mexican drug war:

Interview: A drug lord's lawyer

Mexican cartels go global

Obama's other surge