For most Americans it is hard to understand the level of brutality consuming many regions in Mexico now.
Vicious drug-trafficking cartels fight with each other and the authorities over smuggling routes to the United States and distribution rights in Mexican neighbourhoods.
The bulk of this murderous conflict occurs just south of the 2,000-mile-long U.S. border, so close-by that bullets from gunfire in Mexico have struck buildings on the American side of the fence.
In the nearly four years since Mexican President Felipe Calderon, firmly supported by the U.S. government, launched an unprecedented attack on Mexico's drug kingpins, nearly 30,000 people have been killed.
That averages at more than 20 a day.
Party massacre: Mexican federal police officers stand outside a home after 13 people were killed and 15 wounded in a drug-related attack in Ciudad Juarez
Human toll: Forensic workers carry a body away from the crime scene. It was the second such massacre in a week as rival cartels fight for supremacy
The victims include thousands of police officers, soldiers, public officials, judges and journalists - as the traffickers fight back with powerful weapons, many of them purchased in the U.S.
Often Mexican police find themselves outmanned and outgunned by the criminals.
Terrified Mexican officials have fled across the border seeking political asylum and some Mexican villages have become ghost towns after traffickers killed or pushed out the residents to clear the way for their smuggling operations.
The Mexican trafficking organisations have also crossed deeply into the United States, peddling tons of marijuana, methamphetamine, heroin and cocaine to American drug users, who reward the cartels with an estimated $19bn to $39bn a year, according to the U.S. Drug Enforcement Administration.
Federal authorities say Mexican traffickers are now entrenched in at least 270 American cities, running sophisticated and disciplined networks that not only bring the drugs in, but also ship truckloads of cash back to Mexico.
Bloodbath: Nearly 30,000 people have died in the four years since President Felipe Calderon declared a U.S.-backed war on druglords in the country
Unspeakable suffering: the brutal inhumanity of drug gangs have made countless thousands mourn. Shootings, beheadings and torture are commonplace
David Gaddis, the DEA's chief for global enforcement operations, said: 'Mexico and its government are looking as transnational drug trafficking as a national security threat. We, too, have to look at it seriously in our country. It is our country's number one organised crime threat.'
A distinguishing feature of the Mexican drug war is the unspeakable violence played out daily on the streets and posted in graphic detail by newspapers and media websites.
Large-scale gun battles, mass executions, corpses strewn in public, beheadings, torture and grenade attacks have become commonplace.
As of this time, at least a dozen Mexican mayors have been killed in 2010 alone.
A gubernatorial candidate was shot dead on a highway. After a Mexican marine was killed during a raid against a drug kingpin, gunmen massacred the young man's family after his funeral.
He said: 'It's getting worse. I've never seen it at this level before.'
Of particular concern is Ciudad Juarez, Mexico's fourth largest city with a population of 1.3 million people sitting right across the border from El Paso, Texas.
Two major drug cartels and local gangs have been engaged in a vicious battle there over turf and smuggling routes.
Last year alone, 2,800 people were killed there and the death toll this year could be higher.
In two separate incidents within one week this October, gunmen stormed private parties in Juarez homes and opened fire.
In the first massacre, nine were killed. In the second, thirteen - ranging in age from 16 to 25 years old - died when gunmen stormed a birthday party and opened fire.
Mass graves: This is not Iraq of Afghanistan, but Ciudad Juarez - Mexico's fourth largest city and literally a stone's throw away from the U.S.
Lethal force: Evidence markers show multiple bullet casings where a plain-clothed policeman was killed - again in Ciudad Juarez
The attackers escaped, but authorities suspect the rampage is somehow connected to the ongoing turf war over drugs.
Several other mass killings have occurred in drug rehabilitation facilities. Adding to the terror in Juarez, a remote-controlled car bomb aimed at police was detonated in the downtown area, killing three people and raising concerns over a heightened level of violence.
To lure police to the scene, the bombers shot a man, dressed him in a police uniform, laid him on a street corner and then made an emergency call reporting an officer down. When responders arrived, the bomb hidden in a brief case exploded.
And all this is in one border town alone.
Limited success: Police present Fernando Contreras Meraz, right, along with other alleged drug cartel members and their terrifying arsenal
Unwinnable war: Mexican policemen often find themselves outmanned and outgunned. More than 2,000 people have died in Ciudad Juarez this year alone
Political and law enforcement leaders in both countries agree that American drug users fuel the Mexican trafficking cartels by purchasing their illicit products.
They insist that demand reduction is an important component for calming the violence.
There are also arguments about whether drug legalisation would help, although the predominant view in both countries is that such measures would unlikely be implemented on a national scale.
Another debate is over who is actually winning the fight between the Mexican government and the drug traffickers.
Determined to win: Mexican president Felipe Calderon, who started his campaign four years ago
Tony Payan, a drug cartel expert who teaches at the University of Texas at El Paso, said: 'I don't think it's a winnable war. The reason I don't think it's winnable is that the United States is not addressing the consumption part. It's not doing its part to reduce the market itself.'
David Gaddis, of the DEA, agreed than demand reduction was crucial, but he also pointed to recent arrests of major traffickers, large drug seizures and increased cooperation and intelligence sharing between Mexican and U.S. authorities.
He argued that the extreme violence was the result of traffickers being threatened and cut off from their normal smuggling activities by the Mexican police and military.
He added: 'I see it as very positive, despite the violence that's ongoing throughout Mexico. Desperation results in desperate acts, such as the brutality and the massacres that are ongoing. So we would expect to see continued violence for some time. But at some point, it will yield.'
Others fear that Mexico is now in a long-term spiral toward more bloodshed as the brazen traffickers lash out and fight for control.
Mexico's next presidential election in 2012, they say, is critical, because it will determine whether the current level of pressure on the cartels will continue past President Calderon's administration.
Jose Reyes Ferriz, who just completed a term as mayor of Juarez, insists the United States must fully understand that the current drug war deeply affects both sides of the border and should do more to help.
He said: 'The same gangs that are in Mexico are the same gangs that distribute drugs in the United States. It is a joint problem, and [solving] the problems of Mexico prevents the problem from jumping to the United States."