“We are ‘friends and neighbors,’ as is repeated ad nauseam,” Fernando Belaunzaran, a congressman with Mexico’s left-wing Democratic Revolution Party, tweeted this week, “but the U.S. is about to militarize the border with Mexico as if we were at war.”

“Neighbors don’t do this to each other,” Univision news anchor Jorge Ramos wrote in the newspaper Reforma.

On a national radio show, Lorenzo Meyer, a respected columnist and academic, suggested that Mexico retaliate by kicking out CIA and Defense Department officials who are collaborating with the government in the fight against drug cartels. Or perhaps, Meyer mused, Mexico could get back at the U.S. by refusing to accept any more American retirees.

The proposed spending spree at the border — which supporters have labeled a “surge,” after the 2007 U.S. troop increase in Iraq — was included as an amendment to a broader immigration bill that appears almost certain to pass in the Senate this week. The additional spending would add nearly 20,000 Border Patrol officers, roughly doubling the current force. It would also fund the completion of 700 miles of border fencing and 24-hour surveillance flights by drones.

The Senate voted 67 to 27 on Monday to end debate on the amendment. Supporters are hoping that a lopsided approval of the immigration reform bill in the Senate will build momentum for the proposal as it heads to the House of Representatives.

In the lower chamber, some conservative lawmakers do not want to support the bill’s provision of a “path to citizenship” for unauthorized immigrants, particularly because they fear it will encourage more people to sneak in. But supporters of the surge are hoping to convince skeptical House members that slipping across the border will become far more difficult.

The plan’s American critics include immigrant rights advocates, budget hawks and civil libertarians wary of the expanded surveillance capabilities the Border Patrol would be granted. In Mexico, most of the complaints have come from the left, whose leaders have reiterated the long-held opinion here that U.S. border policy, with its walls, fences and armed border agents, is an insult to their nation.

A number of critics also have taken aim at the government of President Enrique Peña Nieto for not speaking out more forcefully.

“The passivity and negligence of his government is incomprehensible; it’s as if this had nothing to do with him, as if this was not going to seriously affect millions of Mexicans,” Ramos, the TV anchor, wrote in his column Sunday.

Peña Nieto’s team has chosen to hang back from the immigration debate north of the border, apparently out of fear that any cheerleading for the cause could be construed by American conservatives as unwarranted meddling. Former Mexican President Vicente Fox’s efforts to persuade Americans to accept immigration reform in 2001 led to a substantial backlash.

Fox’s former foreign secretary, Jorge Castañeda, who helped lobby for a change in immigration law in 2001, said the Mexican government needed to speak out about the plan.

“Mexico can’t say nothing in the face of a reform that includes doubling the number of Border Patrol agents,” he said in a radio interview Monday. “It strikes me as shameful.”

On Tuesday, Foreign Secretary Jose Antonio Meade delivered a measured statement in which he reiterated the government’s contention that U.S. immigration reform would help millions of Mexican migrants.

But fences, Meade said, “are not the solution to the phenomenon of migration, and aren’t consistent with a modern and secure border. They don’t contribute to the development of the competitive region that both countries seek to promote.”

The apprehension of Mexicans at the U.S. border has been trending dramatically downward since fiscal 2000, when 1.6 million Mexicans were detained. In fiscal 2012, the number was 262,000. It’s likely that fewer Mexicans have been trying to cross in light of the sputtering U.S. economy, stricter border control and fear of Mexican criminals who prey on migrants.

U.S. government statistics show that the number of non-Mexicans apprehended at the border, most of whom were Central Americans, also declined from fiscal 2005 to 2011. But the number doubled from 2011 to 2012, to 94,000, probably a result of rising violence and instability in several Central American countries.

Maria Garcia, the president of the Mexico City-based Aztlan Binational Migrants Movement, said that increased border enforcement would force migrants to find even more dangerous and remote places to cross the border, putting their lives at greater risk. She also doubted that a more heavily fortified border would do much to scare off migrants seeking better wages.

“Hunger is too strong,” she said. “They’ll keep risking their lives.”

But Alfredo Rodriguez, a 59-year-old hardware store clerk, said he could live with the border plan if the U.S. gave Mexicans more legal avenues for employment, such as temporary work visas. In any case, he said, the Americans were within their rights to beef up their security.

“If you invade someone’s property,” he said, “obviously, there are going to be consequences.”

richard.fausset@latimes.com

But six months into his term, Mancera, is fighting accusations that he has mishandled the highest-profile case of his mayoral career: the disappearances last month of 12 people from a bar in the heart of Mexico City.

The case remains unsolved, and the criticism of Mancera, a potential presidential candidate for the left-wing Democratic Revolution Party, or PRD, has been withering.

Mancera suffers from “political autism,” wrote a columnist on the website Sin Embargo. The mayor has not proved to be “a distinct or distinguished head of government,” declared a writer for Proceso newsmagazine.

Perhaps even worse for Mancera is that the disappearances, along with other recent acts of violence, have sparked a national debate about whether Mexico City is lapsing into a period of destabilizing drug-gang violence after several years as an oasis of calm compared with other Mexican cities.

Many think the answer is no. But then again, nobody knows for sure.

“I would like to believe, as an inhabitant of this city, that it is not, but I cannot rule it out,” said Juan Francisco Torres Landa, secretary of the civic group Mexico United Against Crime.

The capital’s reputation as a haven from cartel violence in recent years has made it a magnet for Mexicans whose cities have been beset by shootouts, beheadings and streets blockaded by burning cars. But horrors loom nearby, particularly in the neighboring states of Morelos, the province of the Beltran Leyva cartel, and Mexico, which is dominated by the cartel known as La Familia.

Mexico City is by no means perfect. The U.S. State Department says armed robberies, street crime and kidnappings are “daily concerns.” The 2011 homicide rate of 8.8 per 100,000 residents in the federal district, which encompasses the capital, was roughly one-tenth the rate for the northern state of Chihuahua.

Occasionally, there are outbursts of spectacular public violence of the kind considered a cartel-war hallmark. Last June, federal police said to be protecting a drug smuggling operation killed three fellow officers in the middle of the bustling Mexico City airport.

As a mayoral candidate, Mancera took some credit for the plummeting city crime rate during his time as top prosecutor, including a 12.5% reduction from 2010 to 2011, under the administration of Mayor Marcelo Ebrard. Mancera won the election handily and took office in December.

But even if Mancera can boast that he helped reduce the high levels of crime that once beset Mexico City, it would be difficult for him to ensure a safe environment if organized crime groups have in fact decided to launch a period of terror.

The mayor last week pressured his team to solve the case of the 12 disappearances, telling reporters that “no one is guaranteed a place in my government if they don’t get results.” On Tuesday, the city prosecutor’s office announced that the head of the missing persons bureau, Francisco Carlos Trujillo Fuentes, had stepped down and was being replaced.

Numerous theories exist as to why safety improved in this city of 20 million people during Ebrard’s tenure.

Supporters say the Ebrard team was wise to install thousands of video cameras, hire sharp, innovative police leaders and develop social programs to give kids alternatives to crime. Others suspect that the drug cartel bosses have designated Mexico City as a “safe zone” for their families, which has prevented it from becoming an urban battleground the way cities such as Ciudad Juarez, Monterrey and Guadalajara have in recent years.

Jorge Chabat, a professor at the city’s Center for Economic Research and Teaching, said cartel bosses may have been operating under the assumption that major crimes would generate much more attention in the media-saturated capital than elsewhere and result in more heat from authorities.

A report from the Mexico City Citizen Council shows some homicide and gun-related statistics up slightly in the first five months of this year compared with the same period last year. But auto thefts and home-invasion robberies have declined.

Torres said the May 26 disappearances of the 12 young men and women, whose ages ranged from 16 to 34, garnered more media attention than other similar crimes because they occurred in the Zona Rosa, or Pink Zone — a centrally located, formerly trendy neighborhood that has fallen on hard times but is nonetheless well known to the Mexican elite.

In tougher, working-class neighborhoods, Torres said, “they’d probably say, ‘Why are you guys so concerned about this? This is what happens every day in this city.'”

The details of the disappearances are murky. Family members said the bar patrons had been stuffed into SUVs by armed, masked men, a hallmark of mass kidnappings in other Mexican cities. But city prosecutor Rodolfo Rios has shared surveillance tapes that show the bar patrons being loaded into a number of compact cars by men who do not appear armed or masked. Rios said authorities could place only eight of the 12 missing people at the bar.

Rios said the disappearances may have involved a rivalry between local drug gangs. The missing all hail from Tepito, a neighborhood notorious for counterfeiting and other criminal operations.

Prosecutors have acknowledged that one of the missing, 16-year-old Jerzy Ortiz Ponce, is the son of Jorge “The Tank” Ortiz Reyes, the incarcerated leader of a Tepito neighborhood drug gang. Another of the missing, Said Sanchez, is the son of Alejandro “El Papis” Sanchez, who is serving time for homicide, robbery and extortion, according to local news reports.

On June 6, two masked gunmen entered a gym in Tepito and killed four men. Authorities do not believe the attack is related to the disappearances. More recently, a Mexican journalist revealed that five other missing people were last seen at another bar in a different part of town.

In a separate incident in early May, the grandson of the late Malcolm X, Malcolm Shabazz, was killed in a fight at another Mexico City bar and two suspects were arrested.

Mancera’s government, which has sent hundreds of additional police officers to Tepito and the Zona Rosa, has vowed to watch over nightclubs to prevent further disappearances.

The mayor has denied that the Zona Rosa disappearances had anything to do with the drug cartels and that cartels are operating in the capital.

Torres and others think that Mexico’s big, infamous, multinational criminal organizations are certainly hanging around the megacity, even if they have been keeping a low profile.

Chabat said that Mexico City is home to criminal groups of all sizes. Some of the smaller ones, he said, though not technically cartels, probably have close links to the larger groups.

Ultimately, if Mancera wants to stay alive politically, he will almost certainly be expected to keep all of them, big and small, in check.

richard.fausset@latimes.com

Cecilia Sanchez of The Times’ Mexico City bureau contributed to this report.