Ed Vulliamy insists that he hates war. The award-winning foreign correspondent, whose dispatches from war-shredded regions for The Observer have twice earned him the accolade ‘international reporter of the year’, claims that he is not like some of his colleagues who relish the terrible anarchy of war. “Some correspondents love it,” he says. “It gives them a rush, they find it exciting. I hate it. I hate violence. That’s why I write about it.”

His new book, Amexica, is about the US-Mexico borderland, a dangerous area engulfed in a murderous tug-of-war between Mexican drug cartels and the authorities. The conflict has no artillery lines or trenches, but is horrifyingly murderous nonetheless; at least 28,000 people have been killed in Mexico since 2006 because of the gangs who vie for control of the highly lucrative drugs trade into America.

“It’s very much a 21st-century war,” says Vulliamy, who spent four months on a sometimes highly fraught road trip, zigzagging the 2,000-mile border. “It’s about nothing, in this post-political, post-moral era of greed. It’s not even really about smuggling. Most of the deaths are now for the street corner. The narcos are all about strutting their stuff. You’ve got to have the latest application on your phone; have to have the right car. It’s all about greed.”

Vulliamy first visited in 1981, as a tourist inspired to make the journey from El Paso to Juarez (the two cities sit cheek by jowl, separated by the border) by Bob Dylan’s Just Like Tom Thumb’s Blues. Juarez was a ‘salacious place full of audacity’, Vulliamy found, but not blighted by guns and gang culture. When he returned, two decades later, however, the city, along with much of the rest of North Mexico, had “imploded”.

“The most extraordinary thing I saw on my trip was what greeted me on arrival in Juarez. How many times in one’s life is one going to see a decapitated corpse, with hands handcuffed behind the back, hanging from a bridge?”

Although his book concerns itself with violence that has a “decadent, pointless, perverse ingenuity to it”, it is also about the borderland as a distinct geographical area. “It is a place of dichotomy. It’s porous and harsh, there’s a fence and there are lasers, there’s national guard and border patrol, and yet a million people cross it every day, to shop, to go to school.”

Much of the area’s woes are due to the “maquiladora” factories that sprung up in Mexico to supply cheap manufacturing for the neighbouring US. When Asia became an even cheaper source of labour, the factories closed, creating a vacuum. “People fled and shanty towns emerged into which the gangs moved,” explains Vulliamy. “People got jobs on the ladder of the narco trade and killing industry. There’s always plenty of work.”

He bubbles with indignation as he mulls over the causes of Mexico’s current troubles. Demand for drugs in both America and Europe is central to the issue of the widespread gang violence that now infuses the central American state. “This number of people dying just so that wretched kids in South Wales fry their brains with metamphetamines and so that the glitterati can sniff white powder in the Gaucho Club in London; it makes me sick. In an age of touchy-feely consumerism, when we are meant to be so aware about where our cappuccino comes from, nobody stops to ask how many died so that Amy Winehouse can get powder up her nose.”

Vulliamy, who lives in West London and is the son of children’s author Shirley Hughes, says that a sense of rage has always propelled him. A self-confessed ‘ultra-leftist’ as a student of politics, philosophy and economics at Oxford, when he spent most of his time in Northern Ireland writing a thesis on the Troubles, he is infuriated by the sight of London commuters heading out to work, drone-like, “in the ghastly rush hour, unquestioningly getting on with it all”. “I’ve always been interested in people who struggle for what is right,” he says.

His reporting has taken him to dangerous places. His 83-year-old mother thinks he’s “completely mad”. “The more experienced I get and the more I think I know what I’m doing, the more she worries.”

He also notes with surprising candour that he has had to pay a significant personal price for his work. “This isn’t the sort of thing one can do by halves,” he says with a wistful note in his voice. “But it is a great regret to me that I missed so much of my family growing up, doing all this caper. And it has cost me my marriage, I would say.”

l Ed Vulliamy will talk about Amexica at Blackwells on Wednesday, November 10 at 7pm.