The report by the Violence Policy Center advocacy group, titled “The militarization of the U.S. civilian firearms market,” says that the civilian firearms industry in the United States has been in decline for several decades, partly because of the growing popularity of video games and the fact that younger Americans and immigrants are less prone to buying guns.

While the U.S. population grew by 24 percent in the two decades ending in 2000, the U.S. production of small weapons fell by 33 percent, it says.

So what has been the gun industry’s response? Try to sell bigger, more-lethal weapons, many of which are used in mass shootings, attacks on U.S. law enforcement officers, or are sold to the Mexican and Central American drug cartels.

Mexican President Felipe Calderón said in Washington last year that more than 80 percent of the guns and assault rifles seized in Mexico that have been traced come from the United States. And in the United States, there are 10 times more people killed and injured annually by guns than there were victims of the 9/11 terrorist attacks, the report says.

“The U.S. civilian gun market has become a militarized bazaar,” it says. In order to increase revenues, U.S. gun manufacturers are bombarding consumers with ads portraying the message that civilians — just like real soldiers — can easily own military-style weapons, it says.

For instance, faced with a 1986 law that bans the sale of machine guns to civilians, the gun industry has in recent years promoted sales of semiautomatic assault weapons that are similar to AK-47 and M-16 military assault rifles.

Unlike machine guns, semiautomatic weapons require that their trigger be pulled back separately for each bullet. But gun manufacturers are increasingly adding new features to their semiautomatic weapons — such as detachable ammunition magazines that hold as many as 75 rounds of ammunition — that turn their products into formidable killing machines.

“The difference between semiautomatic rifles and machine guns is negligible,” the study’s author, Tom Diaz, told me. “Semiautomatic rifles are just as deadly. You can actually be more accurate, because the gun itself doesn’t climb like a machine gun.”

Now that the violence along the U.S.-Mexico border and the killing of U.S. law enforcement officers are drawing growing media attention on U.S. gun manufacturers’ sales of military-style weapons, the gun lobby has rebranded semiautomatic assault weapons as “modern sporting rifles.” But there’s nothing sports-related about these weapons, Diaz said.

I called the National Rifle Association’s press office about a half-dozen times over several days for an official reaction to the report, but was told that all NRA spokespersons were too busy to respond.

Other pro-gun activists told me that semiautomatic weapons are used for sports, and that only a small percentage of violent deaths in the United States are caused by semiautomatic weapons. In addition, they say that many of the U.S.-made heavy weapons used by Mexico’s drug cartels are being purchased from corrupt Mexican army officers.

My opinion: With more than 40,000 deaths in drug-related shootings in Mexico over the past five years, an escalating death toll in Central America and the Caribbean, and U.S. policemen being outgunned by criminals in many cities, the growing sales of these military-style weapons have become a regional problem that requires regional solutions.

The Obama administration should seek congressional ratification of a 1997 regional treaty known as CIFTA, which tries to crack down on illicit firearms trafficking in the Americas. President Barack Obama has said he supports CIFTA, but isn’t doing much to get it passed by Congress.

And Latin American countries should step up diplomatic pressure on the United States to get Congress to reinstate a ban on assault weapons that was allowed to expire in 2004, as well as to get Obama to issue an executive order to stop imports of military-style weapons that often end up in the hands of Mexican and Central American drug cartels.

How many more people have to die in mass shootings across the hemisphere before we put an end to this madness?