With the Iraq war over and the American presence waning in Afghanistan, U.S. security contractors are looking for new prospects in Mexico, where spreading criminal violence has created a growing demand for battle-ready professionals.

After years of lucrative work in the Middle East and Central Asia, where their presence has been occasionally marred by incidents of excessive force and misconduct, contractors and private security firms of varying sizes and specialties are being drawn into a conflict closer to home. But Mexico’s restrictive gun laws mean that foreign contractors must enter the bloody drug war unarmed as they take jobs ranging from consulting and technical training for the Mexican military to guarding business executives from kidnapping gangs and extortionists.

Virginia-based DynCorp International has job openings in Mexico for aviation instructors and mechanics. The New York consulting firm Kroll hires anti-kidnapping specialists to protect Mexican business executives.

The companies are beckoned by swelling pots of public and private contracting gold. In November, the Pentagon’s counter-narco-terrorism program office solicited bids on more than $3 billion in contracts worldwide, with an unspecified amount destined for operations in Mexico. The State Department has pledged nearly $2 billion in drug war aid to Mexico since 2008, much of it available to U.S. companies that can provide equipment or services to the besieged Mexican state.

Security spending by private companies in Mexico and the Mexican government has also surged. Since President Felipe Calderon deployed Mexico’s military against the country’s drug kingpins in December 2006, the number of armed private security firms in the country has doubled, Mexican federal police statistics show. But while there are 1,400 licensed firms in good standing, analysts say there may be an additional 10,000 operating without proper authorization.

Still, despite Mexico’s potential for highly remunerative work, experts caution that it will never equal the bonanza that U.S. companies found in Iraq and Afghanistan.

For one, the money available in Mexico doesn’t measure up to the cash that flowed through the wars in Iraq and Afghanistan, where the U.S. government spent more than $200 billion on private contractors over the past decade.

Gun law restrictions

Then there’s the issue of Article 27 of Mexico’s firearms code, necessary reading for anyone tempted to make a transition from Kabul or Baghdad to Mexico’s urban badlands. It essentially bans foreigners from carrying guns in Mexico — a deal-breaker for many would-be soldiers of fortune, despite their growing interest in the country, said Michael Braun, former DEA operations chief and now a partner with Spectre Group International LLC, a private security firm based in Alexandria.

“The Mexican government is not going to allow U.S. contractors to be armed in Mexico, and I can tell you that alone will cause many companies large and small to not even consider performing work there,” Braun said.

“The Mexican government and the Mexican people are extremely sensitive when it comes to these questions of sovereignty, and we need to respect that,” he added.

Mexico maintains some of the tightest gun-control laws in the hemisphere, even as drug gangs amass formidable arsenals of AK-47 assault rifles, grenade launchers and other military-grade weapons. While foreigners who are permanent residents in Mexico can get permits to own certain firearms for hunting or home defense, Mexican law prohibits non-citizens from working as armed security guards or carrying concealed weapons for self-defense.

That has a broad, chilling effect on U.S. contractors contemplating work in Mexico, even among those who do not directly work in security details as bodyguards, analysts say. Many private security contractors are military veterans who are accustomed to keeping at least a handgun for self-defense, and they balk at the thought of going unarmed into one of Mexico’s hot zones, such as Ciudad Juarez or Nuevo Laredo.

“A lot of guys ask me: ‘How do you carry down there?’ And when I say I don’t, they can’t believe it,” said Rick Sweeney, chief executive of California-based SECFOR, which provides personal security services to business executives in several of Mexico’s manufacturing centers, mostly along the border.

Sweeney said he worked as a security contractor in Iraq until 2006. Today, all of his 15 or so contractors are deployed in Mexico. Most are ex-soldiers from Britain and Australia. None is allowed to carry a weapon, so they team with local Mexican companies that can provide firepower.

“Everyone thinks if they worked in Iraq and Afghanistan they can work in Mexico, but it’s a different ballgame,” Sweeney said. “I’m not looking for the guys who come to me and say they’re an expert shot or a black belt. I’m looking for guys who can plan and stay out of trouble, rather than blast their way out of trouble once it starts.”

Partners vital — and risky

Armed private security is a booming business in many parts of Latin America, and demand for personal protection services in Mexico is growing at least 20 percent a year, driven by foreign and local business executives looking to safeguard their families and employees, according to Robert Munks, a senior Americas analyst with London-based IHS-Jane’s, which tracks global security trends.

Foreign contractors who partner with Mexican firms to provide armed guards typically subject those workers to extensive background checks, according to Munks, but contractors are still exposed to considerable risk.

“They have to be incredibly careful about who they partner with,” he said. “A very large percentage of people working in private security are suspected of working with organized crime networks.”

Still, the huge volume of trade between the United States and Mexico often necessitates that American executives cross the border. Companies that do not have much experience in Mexico are especially concerned about sending their staffers, even for short trips, according to Robert Oatman, a Maryland-based security consultant.

“You’re not going to see many executives traveling to Tijuana, or if they do, they’re not spending the night,” Oatman said.

A boom in training

A growing number of former and current U.S. military personnel are also training Mexican security forces in counterinsurgency, electronic surveillance and other techniques honed by the long American engagements in Iraq and Afghanistan.

American security aid pays for some of those programs, while other contractors are paid by the Mexican government, whose spending on security jumped from $1.7 billion in 2005 to more than $12 billion in 2011, according to the think tank Mexico Evalua.

There are no precise figures on the number of U.S. security contractors working in Mexico, but the Pentagon and the State Department spent $635.8 million on counternarcotics contracts in Latin America in 2009, a 32 percent increase from 2005, according to an analysis prepared by the office of Sen. Claire McCaskill (D-Mo.) in June.

The report found that the United States awarded more than $170 million in counternarcotics contracts in Mexico between 2005 and 2009, much of that from the nearly $2 billion in security assistance that Congress has allocated through the Merida Initiative.

Still, analysts say the U.S. role in Mexico will always be limited by sensitivities to the bitter legacy of armed American troops south of the border.

“The U.S. government is afraid of overstepping, given the limited welcome it has in Mexico,” said Nick Schwellenbach, an investigator at the Project on Government Oversight, a District-based watchdog group. “And given the history,” he added.