During January 2011, Anabel Hernández's extended family held a party at a favourite cafe in the north of Mexico City. The gathering was to celebrate the birthday of Anabel's niece. As one of the country's leading journalists who rarely allows herself time off, she was especially happy because "the entire family was there. There are so many of us that it's extremely difficult to get everybody together in one place. It hardly ever happens."

Anabel Hernández had to leave early, as so often, "to finish an article", and it was after she left that gunmen burst in. "Pointing rifles at my family, walking round the room – and taking wallets from people. But this was no robbery; no one tried to use any of the credit cards – it was pure intimidation, aimed at my family, and at me." It was more than a year before the authorities began looking for the assailants. And during that time the threats had continued: one afternoon last June, Hernández opened her front door to find decapitated animals in a box on the doorstep.

Hernández's offence was to write a book about the drug cartels that have wrought carnage across Mexico, taking some 80,000 lives, leaving a further 20,000 unaccounted for – and forging a new form of 21st-century warfare. But there have been other books about this bloodletting; what made Los Señores del Narco different was its relentless narrative linking the syndicate that has driven much of the violence – the Sinaloa cartel, the biggest criminal organisation in the world – to the leadership of the Mexican state.

Her further sin against the establishment and cartels was that the book became, and remains, a bestseller: more than 100,000 copies sold in Mexico. The success is impossible to overstate, a staggering figure for a non-fiction book in a country with indices of income and literacy incomparable to the American-European book-buying market. The wildfire interest delivers a clear message, says Hernández: "So many Mexicans do not believe the official version of this war. They do not believe the government are good guys, fighting the cartels. They know the government is lying, they don't carry their heads in the clouds."

Hernández's book will be published in English this month with the title Narcoland: The Mexican Drug Lords and their Godfathers, so that we in the English-speaking world that consumes so much of what the cartels deal, and which banks their proceeds, might learn the lie of "cops and robbers", of "upright society versus the mafia" – the received wisdom that still contaminates coverage of drug wars and the "war on drugs".

Two writers in particular have been pioneering the struggle to counter this untruth: one is Hernández, and the other is Roberto Saviano – author of Gomorrah, about the Camorra of Naples – who writes in a foreword to Hernández's English edition: "Narcoland shows how contemporary capitalism is in no position to renounce the mafia. Because it is not the mafia that has transformed itself into a modern capitalist enterprise, it is capitalism that has transformed itself into a mafia. The rules of drug trafficking that Anabel Hernández describes are also the rules of capitalism."

By the year 2000, Anabel Hernández had made a name for herself in Mexican journalism, on the daily paper Reforma. But in December of that year, she found herself personally caught up in the murky crossover between state and criminals when her father was kidnapped: a crime the family believes to have been unconnected to his daughter's work.

The police in Mexico City said they would investigate only if they were paid; the family refused, figuring – as sometimes happens – that the police would take the money without taking any action. When Mr Hernández was murdered, Anabel Hernández's resolve to nurture her craft – fearless of, and without illusions about, the establishment – was deepened by the outrage.

Within a year, Hernández had broken a scandal about the extravagance with which the winning presidential candidate, Vicente Fox, had decorated his personal accommodation using public funds – while campaigning on a ticket of economic austerity. Two years later, she was honoured by Unicef for her work on slave labour and the exploitation of Mexican girls entrapped in agricultural work camps in southern California. Before long, Mexico's drug war erupted, and Hernández turned her attention to this most perilous of subjects, and the most powerful man involved: Joaquín "El Chapo'" Guzmán, leader of the Sinaloa cartel. In the depth of its depiction of the world's richest and most influential criminal, Hernández's book leaves every other account far behind.

Puente Grande State prison in Mexico, in which El Chapo ("Shorty") Guzman, head of the Sinaloa cartel was nominally incarcerated, but which he actually ran. Photograph: Getty Images

When Zulema Hernández (no relation) entered Puente Grande prison, convicted of robbery, she cannot have thought herself in for a happy time. But she could never have imagined the consequences of attracting the attention of the jail's most famous inmate, Guzmán, and becoming one of his lovers. The attentions of El Chapo ("Shorty") led Zulema to have two abortions, to being prostituted around the warders like "a piece of meat" and – once released – to her corpse being found in the boot of a car with the letter Z, epigram of Guzmán's main rivals, Los Zetas, carved into her buttocks, breasts and back.

If this appalling tale, past midway through Hernández's narrative, captures the squalidness of Mexico's drug war, another passage illustrates the way Guzmán ran the jail in which he was supposedly incarcerated, inviting his extended family in for a five-day Christmas party. Hernández also recounts the mysterious murders of the one senior public official who tried to expose the corruption at the jail at government level and the only warder who testified to it. And, most important, the fact that Guzmán did not "escape" from Puente Grande, as the lore has it, in a laundry truck – he walked free in police uniform, with a police escort, long after the chief of the prison service and deputy minister for public security arrived in response to the "news" of his escape.

A 2001 photograph shows druglord Joaquin 'El Chapo' Guzman in jail in Mexico. Photograph: Corbis

For this is a book about, to use one of Anabel Hernández's best words, the "mafiocracy", rather than the mafia – about the mafia state. It is about how the old Guadalajara cartel of the 1980s was protected by the Mexican government just as its heir, Guzmán's Sinaloa syndicate, is now. It is about the rise of Genaro García Luna, whom Hernández accuses of being El Chapo's protector at the apex of government. "At first, I thought it would be difficult," she says. "I didn't think people would be ready to believe that the government is lying. That this is all one big lie."

A character appears throughout the book, called simply "The Informant" – one among many Hernández found during her five-year odyssey through the criminal world, and those supposedly fighting it. "And he told me when I started this in 2005: 'Don't do this. You're a woman and it's too dangerous.' But I had to – because of what had happened in my life, and because only when people understand what is going on can they change it."

The threats began when Hernández's book was published in Mexico in 2010 – and their story is interwoven into the book she has since written, Mexico in Flames. By this time she had become a mother of two children. "I received initial warnings that someone in the government wanted to sanction me," she says. "Even that someone wanted to have me killed. I didn't want to believe it, but I was told this on good authority – 'they want to kill you'. I'd come to know official cars well over the years, and one day when I was fetching my little child from school, there it was, one of them, an official one."

Whatever the motive of this menace, "I reported it immediately to the government's human rights commission. They opened a file, and I was allocated 24-hour protection." But then, earlier this summer, a sinister move: the authorities announced their intention to remove the escort, forcing her to cancel a number of trips to afflicted areas of the country to promote the new book.

"I fought the decision," says Hernández, "and they gave me back the escort – but beheaded animals continued to appear on my doorstep even after this, as recently as last June."

A 2005 picture of Rafael Caro Quintero, who was released last month on a technicality. Photograph: Getty Images

When Hernández visits Britain this month, she will be drawing attention not only to the agony of her country, but to the intimidation she has suffered and the murder of scores of her colleagues. This pogrom against the press is no "sideshow" or media obsession with itself – it is strategically integral to Mexico's drug war, and the taking of territory by the cartels.

One of Hernández's friends is the veteran reporter Mike O'Connor, who spent much of his childhood in Mexico, has covered conflict since America's "dirty wars" in Central America during the 1980s and now works full-time on behalf of Mexico's menaced reporters, based in Mexico City for the Committee to Protect Journalists.

"The silencing of the press and killing of journalists is integral to the reality, the big story, of what is happening here," explains O'Connor. "The cartels are taking territory. The government and authorities are ceding territory to the cartels and, for the cartels to take territory, three things have to happen. One is to control the institutions with guns – basically, the police. The second is to control political power. And, for the first two to be effective, you have to control the press."

Furthermore, he says, underlining the theme of his friend's book, "The inability of the government to really solve any of the crimes against journalists during the four years I've been here is a metaphor for its inability to solve crimes against common citizens. They simply cannot do it. And you wonder: if they can't solve these crimes, why not? Is it because they don't want to?"

What does Hernández feel about her less prominent colleagues on local papers, often compromised and threatened by cartels? It is a problem, she says, that "our reporters are not united in the face of these threats and murders", and she intends to "form a federation of solidarity, to build a group, a community, to make us stronger against the cartels and authorities".

"Many of these murders of my colleagues have been hidden away, surrounded by silence – they received a threat, and told no one; no one knew what was happening," she says. "We have to make these threats public. We have to challenge the authorities to protect our press by making every threat public – so they have no excuse."

The timing of this English edition of the book is fortuitous, feeding into the current news like a hand into a glove. The release last month of the cartel boss Caro Quintero by a Mexican federal court made headlines across the world; Quintero had been convicted of a part in the torture to death of a US Drug Enforcement Administration agent, Enrique "Kiki" Camarena in 1985. It's a murder which, in Hernández's account, throws light on both Mexican government and CIA complicity in drug trafficking, a narrative that exposes a deep root of the present drug war.

The court released Quintero on a legal technicality, but Hernández says now: "Mexico's government did nothing to prevent his release. On the contrary, they contributed cover for the release. The one thing nobody wants is Quintero talking about the roles of the Institutional Revolutionary Party [returned to power, and in government during Camarena's murder] and the CIA in the origins of Chapo Guzmán's cartel."

Another major item of news was the capture in July of the Zetas leader Miguel Angel Treviño Morales, and the killing last year of the man he replaced, Heriberto Lazcano. These successes for the Mexican military speak to Hernández's theme: it has long been speculated that any Mexican government's best chance for peace is to return to the so-called "pax mafiosa", a conviviality with – a blind eye towards – the biggest cartel, Guzmán's, whereby the drugs keep flowing in exchange for a cessation of violence, while the official "war on drugs" is fought against his opponents. Of these, the Zetas are by far the most formidable.

"Sadly, I think this is what is happening," says Hernández. "Mexico is exhausted. People will pay anything to live in peace. And this is the strategy; a sponsorship of the Sinaloa cartel, which makes the so-called 'war on drugs' one big lie."

Señores del Narco is not flattered by its English translation, which is sometimes colloquial to the point of inelegance (agent Camarena is described as "a goner", and the mysterious killing of a compromised government official, Edgar Millán, is "a shocker"). That is a shame given the importance of the book and the availability of excellent translators from Spanish. The English edition is, furthermore, regrettably tardy (though hats off to Verso for publishing it), illustrating the Anglophone world's baffling detachment from the death toll of the drug-taking to which it feels entitled.

Hernández is "very pleased my book is being published in English, so it can be read in London and New York where drugs are being sold and taken on every corner, and people can know where every gram of cocaine comes from – corruption and death. I want it published in Britain and America, where the profits are laundered. In your country, where HSBC took Chapo Guzmán's money to 'look after it', and then said they didn't know where it came from. I have studied the laundering networks in depth, and I cannot believe them."

Hernández insists – and this is what places her among the political heretics with regard to the "war on drugs"– that "the violence and the cartels are not the disease. They're a symptom of the disease, which is corruption. The cartels cannot operate without the support of officials, bureaucrats, politicians and police officers – and bankers to launder their money. These people let the narcos do what they do and they are the issue, this is the cancer. I met these people, the narcos. They have no scruples, they're cruel – but in the end, they're just businessmen, all they can see is money. Life, they cannot see."

Anabel Hernández will be speaking at the Frontline Club, London, on 11 September and at Bristol festival of ideas on 13 September

EXTRACT

Mexican Federal Police patrol the surroundings of the Puente Grande State prison (background) in Zapotlanejo, Jalisco State, Mexico. Photograph: AFP/Getty Images

The passages below, extracted from Anabel Hernández's book, describe prison life for Mexican drug barons

El Chapo's women



During his detention in Puente Grande, Joaquín Guzmán killed time with sex, alcohol, drugs, volleyball, and push-ups. Like Hector "El Güero" Palma and Arturo "El Texas" Martínez [two other prisoners], he was well supplied with Viagra and other prowess-enhancing products. Given their age, it seems unlikely they would have been prescribed Viagra, unless of course they suffered from some dysfunction. Witnesses among the prison commanders and warders say the obsession with sex was so great that the three held competitions to see which of them could keep going the longest.

Prostitutes came and went from Puente Grande unimpeded; prison managers referred to them pejoratively as "las sin rostro," the faceless females. They would be brought in official cars, wearing blonde wigs. Prisoners received them in the psychological care section, in the conjugal visit rooms, or in their own cells. If ever there was a shortage, they would get their hands on female staff or inmates, with the connivance of warden Beltrán. These women didn't have much choice. Any who dared to resist the sexual demands of the drug barons had a rough time.

Of all the women El Chapo had at Puente Grande, three stood out: Zulema Yulia, Yves Eréndira and Diana Patricia. Each learned what a hell it is to be the current favourite of a gangster. Their desperate stories blow apart the myth of the "love-struck drug baron".

On 3 February, 2000, Zulema Yulia Hernández, a young woman just 23 years old, was incarcerated in Puente Grande for robbing a security van. Even if she deserved to go to jail, the maximum security facility seemed an excessive punishment. There was no separate wing for women. They were kept in the observation and classification centre, where they had neither the appropriate medical services nor adequate physical protection in the midst of an overwhelmingly male population.

Guzmán's family visits coincided with those of Zulema. She quickly caught El Chapo's eye. The drug trafficker's obsessive nature and the young woman's vulnerable situation were to shape their dark tale. Through one of the members of the Sinaloas, known as El Pollo, Guzmán sent "love" letters to Hernández. The almost illiterate drug trafficker dictated these letters to an unidentified scribe, who embellished them with a dose of drama. Of course, writing to a female inmate was one of the thousands of forbidden things that he was allowed to do quite freely. Very soon, Guzmán began to have intimate relations with the young delinquent barely more than half his age. Their meetings took place in the communications area, aided and abetted by female guards and by the prison management.

The last Christmas in Puente Grande



It was after 10pm on Christmas Eve. The silence hanging over the broad freeway between Guadalajara and Zapotlanejo was broken by the roar of a convoy of SUVs, speeding towards the prison. At the junction outside the gates, there was a temporary checkpoint where perimeter guard José Luis de la Cruz stood watch with a colleague. He'd had specific orders from the deputy director for perimeter security not to let anybody in; he'd even been told to park a pick-up truck across the road to block access to the jail.

When De la Cruz saw the vehicles approaching without switching off their lights, he nervously swivelled his weapon and chambered a round, thinking it could be an attack. The driver of the lead vehicle suddenly slammed on the brakes, opened the door and jumped out. The guard's fears vanished when he recognised the smiling face of prison commander Juan Raúl Sarmiento. "It's us," he shouted jovially, like someone arriving at a party. De la Cruz moved his truck to let the line of vehicles pass. Joaquín Guzmán's relatives were travelling in some of them; Héctor Palma's in others. There was also a big group of mariachis and 500 litres of alcohol for the Christmas party. The sumptuous feast arrived a few minutes later. It had been prepared at the last moment, but the menu was first-class: lobster bisque, filet mignon, roast potatoes, prawns, green salad, and trays of nibbles, with canned sauces to spice up the dishes after reheating.

El Chapo and El Güero had been planning the celebration for weeks. They sent for a brighter yellow paint than that usually used in the prison; the prison guards themselves worked overtime painting the walls. The corridors and cells of units three and four were hung with Christmas lights and decorations. Guzmán's outside gofer, El Chito, had been entrusted with organising the banquet and buying the family gifts, as well as getting special food and drink for the ordinary prison inmates.

Corruption had been rife in Puente Grande for the past two years, but this cynical display of power was unprecedented. The party went on for three days. El Chapo and El Güero's relatives stayed until 26 December, taking advantage of the authorities' extreme laxity. Although it had looked as if the change of government might mean the drug barons would lose their privileges, they were acting with extraordinary confidence. In fact, one of the guests at the party was the prison warden himself; Leonardo Beltrán never let go of the briefcase full of wads the traffickers had given him for Christmas.