I’ve got 23 ziplock bags filled with coca leaves laid out on the rickety table in front of me. It’s been seven hours since the leaves were picked, and they’re already secreting the raw alkaloid that gives cocaine its kick. The smell is pungently woody, but that may just be the mold growing on the walls of this dingy hotel room in the southern Colombian jungle. Somewhere down the hall, a woman is moaning with increasing urgency. I’ve barricaded the door in case the paramilitaries arrive.

I drop half a milliliter of water into a plastic test tube and mash a piece of a leaf inside. As the water tints green, I notice that my hands are shaking. I haven’t slept for two days, and the Marxist guerrillas have this town encircled. But what’s really making me nervous is the green liquid in the tube.

Over the past three years, rumors of a new strain of coca have circulated in the Colombian military. The new plant, samples of which are spread out on this table, goes by different names: supercoca, la millonaria. Here in the southern region it’s known as Boliviana negra. The most impressive characteristic is not that it produces more leaves – though it does – but that it is resistant to glyphosate. The herbicide, known by its brand name, Roundup, is the key ingredient in the US-financed, billion-dollar aerial coca fumigation campaign that is a cornerstone of America’s war on drugs.

One possible explanation: The farmers of the region may have used selective breeding to develop a hardier strain of coca. If a plant happened to demonstrate herbicide resistance, it would be more widely cultivated, and clippings would be either sold or, in many cases, given away or even stolen by other farmers. Such a peer-to-peer network could, over time, result in a coca crop that can withstand large-scale aerial spraying campaigns.

But experts in herbicide resistance suspect that there is another, more intriguing possibility: The coca plant may have been genetically modified in a lab. The technology is fairly trivial. In 1996, Monsanto commercialized its patented Roundup Ready soybean – a genetically modified plant impervious to glyphosate. The innovation ushered in an era of hyperefficient soybean production: Farmers were able to spray entire fields, killing all the weeds and leaving behind a thriving soybean crop. The arrival of Roundup Ready coca would have a similar effect – except that in this case, it would be the US doing the weed killing for the drug lords.

Whether its resistance came from selective breeding or genetic modification, the new strain poses a significant foreign-policy challenge to the US. How Washington responds depends on how the plant became glyphosate resistant. That’s why I’m here in the jungle – to test for the new coca. I’ve brought along a mobile kit used to detect the presence of the Roundup Ready gene in soybean samples. If the tests are inconclusive, my backup plan is to smuggle the leaves to Colombia’s capital, Bogotá, and have their DNA sequenced in a lab.

In my hotel room, I put the swizzle stick-sized test strip into the tube filled with mashed Boliviana negra. The green water snakes up the strip. If the midsection turns red, I’ll know that the drug lords have genetically engineered the plant and beaten the US at its own game. If it doesn’t, it’ll mean that Colombia’s farmers have outwitted 21st-century technology with an agricultural technique that’s been around for 10,000 years.

I first learned about the possibility of herbicide-resistant cocaine eight weeks before I arrived in South America. I was having a quiet Sunday brunch at home in California with a few friends and their Colombian guest. It was a beautiful day; we sat on the deck and chatted about upcoming vacation plans over waffles and grapefruit juice.

The conversation changed when the guest began talking about how he’d spent three years working in the military intelligence branch of the Colombian army, which has been waging a civil war against the guerrillas for four decades. His main assignment was to prevent insurgents from importing weapons and military technology.

After the US helped the Colombian military dismantle the Medellín and Cali cocaine cartels in the ’90s, the guerrillas moved in and took over much of the drug trade. By the late ’90s, rebels controlled more than a third of the country and had the financial clout to intensify the war and protect their newfound position as narcotraffickers. It’s an extremely lucrative business. The coke habit in the US alone was worth $35 billion in 2000 – about $10 billion more than Microsoft brought in that year.

But the most intriguing development he mentioned was regular reports of Roundup Ready coca. “We started to hear about this plant three years ago,” he said. “We understood then that the spraying was not killing it, but nobody wants to talk about it because it might put an end to American aid money.”

US aid to Colombia totaled more than $750 million last year and has been flooding in since 2000, when Congress approved the Clinton administration’s Plan Colombia, a regional anti-narcotics package. About 20 percent of the money was devoted to maintaining a fleet of crop dusters and support planes that make almost daily sorties over the Colombian countryside. (The rest of the money went to economic support, military aid, and police training.) The crop dusters fly high, out of artillery range, until they reach a designated coca field, and then descend to spray the plants with a coating of Roundup. The concept is simple: Kill the coca and there will be no cocaine.

The day after our brunch, I looked up the Herbicide Resistance Action Committee and spoke with Ian Heap, the committee’s chair. Heap is a global herbicide watchdog. If a farmer in Thailand notes that a certain weed is surviving repeated herbicide applications, local scientists will collect a sample and ship it to Corvallis, Oregon, where Heap runs a private laboratory. He is funded primarily by herbicide manufacturers who want to know how effective their products are. I figured he would know something about the reported resistance in coca. “So they’ve finally done it,” he said with a breezy Australian accent. “I’ve been waiting for a call like this for a long time.”

Heap explained that few people knew how to genetically manipulate plants until the early ’90s. Then suddenly, even undergraduates were learning the techniques. At the same time, scientific papers were published that identified CP4, a gene responsible for glyphosate resistance. By the late ’90s, it’s easy to imagine the narcos hiring one unscrupulous scientist to tinker with coca. “Cocaine dealers have a lot of money to do the convincing,” Heap said. “Genetically modifying the coca plant is the most obvious defense against fumigation. If I were a drug lord, it’s what I would do.”

Heap suspects that the US government might keep such a development quiet. The herbicide would still be effective against older, more widely planted coca strains, and, for a while at least, Colombia’s eradication campaign would continue to show impressive results. But eventually, as the modified strain spread, coca cultivation would rise again, and spraying would have no effect. In the interim, farmers growing the new strain would get free weeding. “It’s critical for the war on drugs that this gets independently checked out,” Heap concluded. “But I’m sure as hell not going down there.”

To get another view, I called Jonathan Gressel, one of the world’s foremost experts on herbicide resistance and a professor of plant science at the Weizmann Institute of Science in Israel. “The only surprise is that the drug mafia didn’t do it sooner,” Gressel said when I told him about reports of glyphosate-resistant coca. “Privately, my colleagues and I have been predicting this for years.”

Another way to explain the reported resistance, he said, was that over time the plants developed it naturally after repeated exposure. But in the case of coca, he estimated that it would take 20 years of constant spraying before a naturally resistant strain of the plant would establish itself. It was possible that farmers beat the odds and got lucky in the four years of intensive spraying. “But the most reasonable explanation,” Gressel told me, “is that the illicit narcotics world has genetically engineered the coca plant to be resistant to glyphosate.”

The only way to know for sure was to find the plant and test it.

The early evening air at the El Dorado Airport in Bogotá is thin and rain-scrubbed fresh. Outside, at the curb along the arrivals exit, throngs of people silently hold signs with names on them, but in the murky light it’s hard to see. I file quickly past, heading for a line of taxis, until one sign makes me stop. It has my name on it.

Three days earlier, I’d placed a call to a Colombian geneticist. I explained that I was going to be arriving in Colombia in a few days and would like to talk to him about possible alterations to coca DNA. He cut the conversation short and asked for my flight information, saying he would meet me at the airport. I told him that wasn’t necessary, figuring I’d call him when I got settled in my hotel.

Now he steps out of the shadows and introduces himself. “In Colombia, it is always better to talk in person,” he says. He is a bookish, bespectacled man and seems distracted. “I’ll drive you into town and we can talk.”

We head for the city’s central district in his old, messy car. The streets are narrow, and some of the once-grand stuccoed buildings are graffitied over with guerrilla slogans. He’s either nervous or doesn’t know how to drive, because he keeps stalling at stop signs. The flak-jacketed police that stand on almost every corner swivel their automatic rifles toward us as we lurch past.

We come to a stop in a historic section of Bogotá, and the scientist leads me into an empty, cavelike bar. He chooses a table in the farthest corner. A soccer game plays on a small TV by the entrance. We get two beers, and the scientist waits for the barkeep to go back to the other end of the bar.

“I would prefer it if you don’t mention that we met,” he begins.

He then asks me what I know. I tell him I’m just trying to figure out if this resistant strain exists, and if so, how it came into being. The scientist pauses.

“Nine years ago,” he says, “a friend came to me. He told me that the traffickers wanted someone to modify the DNA. They wanted a glyphosate-resistant plant. The offer was 10 billion pesos. About $10 million.”

“That’s a lot of money,” I say. “Did you do it?”

He smiles wanly. “No, I did not do it. I didn’t want to invite that trouble into my life. These are not people you want to know. They are not good people. And if this fumigation benefits only them, I think that should be known.”

He takes a sip of his beer. “So listen to me. If you can get me samples of the plant, I will extract the DNA and tell you if they have gotten inside the genetic code. If there are no signs of manipulation, then we will know that the farmers have done it on their own.”

We look at each other for a second. It crosses my mind that he might be working for traffickers and will simply destroy the samples and lie about having done tests. If the local kingpins have created a Roundup Ready coca plant, they have a real interest in keeping that quiet. After all, they would be getting a guarantee that farmers will have no choice but to grow their new plant. The scientist’s eagerness to help me and his surprising appearance at the airport make me consider this possibility.

But my guess is that he’s genuinely curious to know the answer himself. I decide to trust him. I stick out my hand and we shake. Five minutes later, we leave the bar separately.

The next morning, I board a DeHavilland twin-engine plane for the two-hour flight into Putumayo province, the country’s main coca-growing region. Colombia produces two-thirds of the world’s cocaine, and most of it has historically come from this southern jungle. Over the past decade, tens of thousands of spraying missions have been flown here. US and Colombian officials insist that 92 percent of the plants sprayed in the region last year have now died. As a result, they say, the guerrillas have been weakened and will soon have to negotiate a surrender.

But the guerrillas aren’t ready to be counted out yet. Just before we board the plane, they announce a paro armado – an armed shutdown of the southern region. If anybody travels, they will likely be shot. It’s meant to be a show of force, a sign the guerrillas can still go on the offensive whenever they choose.

Our pilots don’t think much of it. Puerto Asís, the region’s capital, is heavily guarded by the military. Two years ago, the guerrillas laid siege to the town for nine months – everything had to be airlifted in, and the pilots became accustomed to running the blockade. Now, with the rebels pushed back into the jungle, our pilots calmly throttle up, and 90 minutes later we bounce to a stop on a jungle tarmac. A phalanx of heavily armed soldiers guards the perimeter, and two men with sawed-off shotguns stand beside a cagelike room that serves as the arrivals lounge.

The soldiers don’t hassle me; one of them unlocks the far side of the cage and lets me out onto a partially paved road. A group of men across the street stop talking and watch me until a stocky man with a lazy eye introduces himself as Campo, the driver I had arranged in Bogotá. We get into his bright-red Toyota pickup, and before accelerating out of town he touches a picture of the Virgin Mary glued to a shiny blank CD dangling from the rearview mirror. On the map at the Bogotá airport, Puerto Asís was the last dot at the end of the last road. I watch the town fade behind us as we enter the jungle.

We drive for an hour before we come across the first evidence of violence. An oil pipeline alongside the road has been bombed, and flaming black sludge oozes out of a twisted metal pipe, sending swirling cumulus clouds of smoke half a mile above the forest. The grass below sizzles loudly. Campo keeps the car in the middle of the road. The guerrillas may have booby-trapped the far side with mines – better to stay closer to the flames, which sting my face like a sunburn.

Our destination, La Hormiga, is a jungle outpost of 15,000. It was carved out of the forest 40 years ago to house oil workers but in the ’80s was transformed into a coca-farming boomtown. As we crest a ridge, the town appears below, bounded by a sharply defined line of trees that tower over ramshackle two-story cinder block and concrete buildings.

As we drive down the main drag, I see that one of those shoddy roofs covers a faux marble-floored, air-conditioned shopping palace selling imitation Versace jeans. A lady in red hot pants and a halter top window-shops pulling a pet lamb on a pink leash. A casino with rows of slot machines stands next to a dentist’s office that doubles as a jewelry shop. Over the din from a half-dozen roadside discos, a man with a 3-foot-long megaphone meanders down the middle of the road reading the local news – an amplified town crier.

I spend a sleepless night at the inappropriately named 5-Stars Hotel and rise early to meet Miguel Lucero (aka Don Miguel), the local leader of the National Association of Peasant Land Users, a large farmers union. Don Miguel is a short, quiet man with a distinguished, furrowed face. Before he became a peasant leader he farmed coca, and he knows the region’s farms well. I ask him if he has heard of Roundup-resistant coca.

“Yes,” he says simply. “It is called Boliviana negra.”

“Can you show me some?”

“Yes.”

“Right now?”

“Yes.”

We are hiking through the jungle. The path is narrow, overgrown, and muddy. The knee-high rubber boots I just bought keep getting stuck in the muck, and I have to pull them out with my hands. Don Miguel walks fast and confidently. He has assured me that we are well within the government-controlled territory. The guerrillas, he says, haven’t been here during daylight hours for at least a couple of years.

We come to a makeshift bridge. Two slender tree trunks are suspended over a flooding river the color of milky tea. Thin steel cables run above them to give you something to hold on to. Miguel says that the land on the far side belongs to a coca farmer who now grows Boliviana negra. “Everybody is planting negra now,” he says and steps catlike over the bridge.

I follow, trying not to slip into the river 5 feet below. After climbing a small incline, we come upon an arresting sight: 300 yards of devastation. An entire slope of hillside vegetation has disappeared. There’s only brown-gray dirt, a half-dead tree, and withered coca plants, which I recognize from photographs. “Peruviana blanca,” Don Miguel says, pointing at the dead plants. “Not resistant. This slope was sprayed last year.”

We hike up the ridge, and suddenly there are healthy coca plants stretching to the horizon. On one side of an imaginary line, devastation. On the other, billowing, neck-high coca plants dotting hillsides that are denuded of all other vegetation. “Boliviana negra,” Don Miguel says, pointing at the large bushes. “They were sprayed as well.”

Over a lunch of pounded chicken and french fries back in La Hormiga, Don Miguel tells me that Boliviana negra appeared in the region three years ago and is now spreading rapidly across the countryside – just as the herbicide experts told me it might. The new strain is disseminated via cuttings; farmers cut off stems and sell them. Some farmers, looking to make more money, travel with their cuttings and peddle them around the region. And once a farmer grows a new plant, he can sell his own cuttings. It’s file-swapping brought to the jungle – a highly efficient decentralized distribution chain.

Don Miguel doesn’t know where the strain originated. He has heard rumors of a group of mysterious agronomists who develop better coca plants for the traffickers, but he doesn’t know where they are or anything about them.

He does have a clear sense of how the new plant is affecting his region. At first, he says, the aerial spraying was successful, but now, with the arrival of Boliviana negra, it’s affecting only those who are growing lawful crops. “The truth is that the fumigation drives us to the one thing that will survive – and that is Boliviana negra,” he says. “Not bananas, not yucca, not maize.”

The Colombian and US governments want farmers to grow legal crops, he explains, and in the past have paid them to eradicate coca. But though American embassy officials insist that the spraying campaign is more than 99 percent accurate, Don Miguel says that almost all the farmers he knows and represents report that legal crops are sprayed as well. He says that his own tree farm was sprayed, pushing him to the edge of bankruptcy. If Boliviana negra will guarantee income for farmers, Don Miguel says, they will grow it and have less incentive to discuss eradication with the government.

Not to mention the financial benefits. One hectare of land in Putumayo will produce $100 of corn. The same plot will produce $1,000 of coca. Plus you don’t have to transport the coca – the guerrillas will come to your farm and collect it. So why would anyone grow corn? “Because if you grow coca,” Don Miguel says, “you deal with the guerrillas or the paramilitaries or both, and they kill whenever they want.”

Don Miguel has another fear. He doesn’t believe that the US will tolerate the existence of glyphosate-resistant coca. When the authorities find out that farmers are growing the new coca, he fears it will be only a matter of time before they switch to a new herbicide.

He has reason for concern. Last summer, documents show, anti-narcotics officials at the US embassy in Bogotá quietly approached Colombia’s president, ‘lvaro Uribe, and asked him if he’d consider switching from Roundup to Fusarium oxysporum, a plant-killing fungus classified as a mycoherbicide. Some species are known to attack coca; in the early ’90s, a natural Fusarium outbreak decimated the Peruvian coca crop.

But Fusarium is not a chemical – it’s a fungus, and it can live on in the soil. A proposal to consider using it in Florida in 1999 was rejected after the head of the state’s Department of Environmental Protection found that it was “difficult, if not impossible, to control [Fusarium’s] spread” and that the “mutated fungi can cause disease in a large number of crops, including tomatoes, peppers, flowers, corn, and vines.” A switch to Fusarium would, at the least, be an escalation in the herbicide war and a tacit acknowledgment of glyphosate’s failure. It could also turn out to be the A-bomb of herbicides.

Still, according to a letter sent from the State Department to Colombia’s US ambassador, Uribe was “ready to learn more.” The letter, dated October 3, 2003, laid out steps for moving this plan forward, but when I spoke to officials at the embassy, they vehemently denied they are considering a herbicide switch. They stated that they are thrilled with the success of Roundup.

Don Miguel admits that on one level, the spraying has been highly effective. Almost all the old strains of coca have been eradicated. What’s left are small plots of Boliviana negra, but these have become more productive, in part because the spraying has killed all the other plants competing for nutrients.

US officials point to the eradication results of the past three years and argue that the plant could not possibly be resistant. A high-ranking US anti-narcotics official who declined to be identified told me that she had never heard of Boliviana negra, la millonaria, or any Roundup Ready coca plant. Another American official began our conversation by saying, “So you’re here to talk about the nonexistent glyphosate-resistant coca?” And then, more forcefully, “These campesinos have zero education. They can’t be trusted to know whether a plant is resistant to glyphosate.” Nonetheless, I was assured that a helicopter would be dispatched to Putumayo to search for samples. Even amid increasing reports of resistant superstrains, officials have yet to find any evidence of them.

Perhaps they haven’t been to La Hormiga. Everyone I talk to here knows about the resistant plant. Three hours after leaving the coca fields, I attend a meeting of two dozen heads of local farmer cooperatives – they represent more than 5,000 farmers in Putumayo – and they nod knowingly when asked about the new breed. “Nobody listens to us because they think we are dumb farmers,” says one man. “The Americans are arrogant. They don’t talk to the people who live here. We are the ones who are sprayed. We are the ones who live with the plants.”

That evening, I meet Fabio Paz, the energetic mayor of La Hormiga, at his simple concrete house. Paz is 32 and excited to be mayor, despite the fact that in the past three years guerrillas have assassinated more than 30 mayors. He wears jeans and a baggy shirt and does not look like an important man. But two plainclothes guards stand outside while we talk, and his armor-plated SUV is parked in front of the window, presumably to deflect any gunfire or bomb blasts.

“Boliviana negra is like goaaaal for the coca farmers,” the mayor shouts, jumping to his feet and yelling “goal” like a crazed Latin American soccer announcer. “Maybe the narcos bought someone off at Monsanto. There would be poetic justice in that.”

Paz doesn’t know where the strain came from, though he assumes Bolivia, because of the name. He also believes that once refined, it produces a different high than older strains. Either way, he says, farmers are now planting only Boliviana negra: “You can’t give away the other types of coca now.”

When I tell him that I am having trouble getting more than a handful of negra samples because of the guerrilla clampdown, he calls in Chucky, one of his bodyguards. Chucky is short and baby-faced, with an emotionless gaze and a handgun tucked in the waistband of his jeans. The mayor tells me that his name isn’t really Chucky; they just started calling him that after they saw Child’s Play, the horror movie about a child’s doll possessed by a serial killer named Chucky. Paz pronounces it “Shooky.”

“Chucky can collect samples for you,” Paz offers.

Chucky stares at me blankly and nods. I ask if he can identify the strain, and he nods again. Chucky, the mayor explains, was a coca leaf picker before he became a bodyguard.

Twenty hours later, Chucky knocks on my hotel room door. From under his shirt, he pulls out a stack of ziplock bags filled with coca leaves. “Boliviana negra,” he says and points at some of the leaves that have yellow blotches on them. He says those were sprayed a couple of weeks ago. In some cases, he says, the leaves fall off and then regrow after spraying. In other plants, the leaves stay on. This is an important piece of information. A genetically modified plant would be impervious to glyphosate.

It takes me a few minutes to arrange a mobile laboratory on the simple wooden table in my room. When placed in water with macerated soybean and canola, a chemical in the plastic test strip will bond with CP4 ESPS, a protein produced by the Roundup Ready gene. If the protein is present, the chemical turns a section of the strip red.

The problem is, the strips were made specifically to test soybean and canola, not coca. I would rather not travel to Bogotá with a backpack full of coca leaves, but after a series of the tests fail to detect the gene, I realize I have no choice.

By the time I get back to the airport in Puerto Asís, the leaves are giving off a pungent odor of broken twigs even though they’re wrapped in a combination of dirty socks and ziplock bags at the bottom of my backpack. Security at the airstrip is almost nonexistent. A stout, mustachioed woman in olive-green fatigues rifles through my bag. No x-rays, metal detector, or even a pat-down. But at the last minute, she demands that my bag be placed in the hold underneath the plane to better balance the plane’s weight.

I am nervous about landing in Bogotá and dealing with internal customs agents. But before we reach the capital, the plane stops in a city called Neiva to pick up more passengers. While we’re sitting on the runway, the hold is opened and a group of soldiers with a German shepherd approaches. A wave of nausea hits me.

The dog puts two paws up on a trolley carrying the new passengers’ luggage. It sniffs around and then drops back down. I watch with terror as the soldiers stand around chatting for a few minutes. I imagine scenes from Midnight Express, where the dumb American drug smuggler wastes away in a Turkish prison. I promise myself that if I make it out of this, I’ll never smuggle anything again. The dog casually sniffs the wheels of the trolley, and then the group turns and walks away. The hold is closed and we take off again.

We land in Bogotá. There are no internal customs officers at the arrivals terminal. I catch a cab and sink into the backseat. The ride into town is blissful.

The next morning, I take a taxi to the laboratory of the scientist I met on my first night in Colombia. The leaves spent the night jammed among tiny bottles of Chivas Regal in my hotel minibar, and some have turned black. But the scientist assures me that this is not a problem. He smells them and his eyebrows go up. “Very good,” he says and locks the door to the lab. It will take him a month to complete the tests.

Four weeks later, the scientist sends me an email saying that he has completed the DNA analysis and found no evidence of modification. He tested specifically for the presence of CP4 – a telltale indicator of the Roundup Ready modification – as well as for the cauliflower mosaic virus, the gene most commonly used to insert foreign DNA into a plant. It is still possible that the plant has been genetically modified using other genes, but not likely. Discovering new methods of engineering glyphosate resistance would require the best scientific minds and years of organized research. And given that there is already a published methodology, there would be little reason to duplicate the effort.

Which points back to selective breeding. The implication is that the farmers’ decentralized system of disseminating coca cuttings has been amazingly effective – more so than genetic engineering could hope to be. When one plant somewhere in the country demonstrated tolerance to glyphosate, cuttings were made and passed on to dealers and farmers, who could sell them quickly to farmers hoping to withstand the spraying. The best of the next generation was once again used for cuttings and distributed.

This technique – applied over four years – is now the most likely explanation for the arrival of Boliviana negra. By spraying so much territory, the US significantly increased the odds of generating beneficial mutations. There are numerous species of coca, further increasing the diversity of possible mutations. And in the Amazonian region, nature is particularly adaptive and resilient.

“I thought it was unlikely,” says Gressel, the plant scientist at the Weizmann Institute. “But farmers aren’t dumb. They obviously spotted a lucky mutation and propagated the hell out of it.”

The effects of this are far-reaching for American policymakers: A new herbicide would work only for a limited time against such a simple but effective ad hoc network. The coca-growing community is clearly primed to take advantage of any mutations.

A genetic laboratory is not as nimble. A lab is limited by research that is publicly available. In the case of Fusarium, the coca-killing fungus and likely successor to glyphosate, there is no body of work discussing genetically induced resistance. If the government switched to Fusarium, a scientist would have to perform groundbreaking genetic research to fashion a Fusarium-resistant coca plant.

The reality is that a smoothly functioning selective-breeding system is a greater threat to US antidrug efforts. Certainly government agents can switch to Fusarium and enjoy some short-term results. But after a few years – during which legal crops could be devastated – a new strain of Fusarium-resistant coca would likely emerge, one just as robust as the glyphosate-resistant strain.

The drug war in Colombia presupposes that it’s eventually possible to destroy cocaine at its source. But the facts on the ground suggest this is no longer possible. In this war, it’s hard to beat technology developed 10,000 years ago.

Contributing editor Joshua Davis (jd@joshuadavis.net) wrote about wiring the apocalypse in issue 12.04.