The case of the three Malians was one of dozens that the D.E.A. said fit the description of the narco-terrorism statute. Illustration by Ben Wiseman

In December, 2009, Harouna Touré and Idriss Abdelrahman, smugglers from northern Mali, walked through the doors of the Golden Tulip, a hotel in Accra, Ghana. They were there to meet with two men who had offered them an opportunity to make millions of dollars, transporting cocaine across the Sahara. Touré wore a dashiki, and Abdelrahman had on tattered clothes and a turban that hid much of his face. They tipped the guards at the entrance and then greeted Mohamed, a Lebanese radical, in the lobby. Mohamed took them up to a hotel room to see David, a drug trafficker and a member of the Revolutionary Armed Forces of Colombia, or FARC. “Hola, Colombiano,” Touré said, as he entered the room. Abdelrahman tried to call David “007” in Spanish, but said “477” instead. David, who was dressed in a short-sleeved pullover and Bermuda shorts, laughed and offered his guests bottles of water.

Touré and Abdelrahman came from Gao, a parched and remote city in northern Mali which has long been used as a base for smuggling of all kinds, from immigrants to cigarettes. In recent years, the surrounding region has also been the scene of conflict between violent bands of nomadic insurgents, including members of Al Qaeda in the Islamic Maghreb (AQIM). During months of meetings and phone calls, David and Mohamed had told Touré that the FARC had some thirty thousand fighters at war with the United States, and that it wanted to work with Al Qaeda, because the groups shared the same enemy. “They are our brothers,” Mohamed said. “We have the same cause.” Touré had explained that he had connections to the organization: he ran a transport company, and, in return for safe passage for his trucks, he provided Al Qaeda with food and fuel.

Still, David remained skeptical. He needed assurances that Touré’s organization was up to the task. The FARC had a lot of money riding on the deal and was willing to pay Touré and Abdelrahman as much as three thousand dollars per kilo, beginning with a fifty-kilo test run to Melilla, a Spanish city on the North African mainland. Loads ten times that size would follow, David said, if the first trip went well.

“If you’re done, I’m going to speak,” Touré said. He told David and Mohamed that he was tired of all the “blah, blah, blah.” He had operatives along the smuggling route, which stretched from Ghana to Morocco. Abdelrahman, whom Touré had introduced as the leader of a Malian militia, said that he had hired a driver with links to Al Qaeda. They had also bribed a Malian military official, who would help them cross the border without inspection.

David was reassured. “I want us to keep working together, because we’re not doing this for the money—we’re doing this for our people,” he said.

Two days later, Touré and Abdelrahman went back to the Golden Tulip to collect their initial payment. Oumar Issa, a friend from Gao who was also involved in the plan, waited at another hotel to receive his portion. Instead, the smugglers were met by Ghanaian police officers. David and Mohamed, it turned out, were not drug traffickers but undercover informants for the United States Drug Enforcement Administration. Within days, Touré, Abdelrahman, and Issa were turned over to the D.E.A., put on a private jet, and flown to New York, where they were arraigned in a federal courthouse. They were charged under a little-known provision of the Patriot Act, passed in 2006, which established a new crime, known as narco-terrorism, committed by violent offenders who had one hand in terrorism and the other in the drug trade.

In announcing the charges, Preet Bharara, the U.S. Attorney for the Southern District of New York, said, “As terrorists diversify into drugs, they provide us more opportunities to incapacitate them and cut off funding for future acts of terror.” The case marked the first time that the narco-terrorism provision had been used against Al Qaeda. The suspects appeared to be precisely the kind of hybrid whom the law, which does not require that any of the targeted activities take place in the U.S., had been written to catch. Michele Leonhart, the D.E.A. administrator at the time, said, “Today’s arrests are further proof of the direct link between dangerous terrorist organizations, including Al Qaeda, and international drug trafficking that fuels their activities.”

As the Malians’ case proceeded, however, its flaws became apparent. The defendants emerged as more hapless than hardened, childhood friends who believed that the D.E.A.’s informants were going to make them rich. “They were lying to us. And we were lying to them,” Touré told me from prison. Judge Barbara Jones, who oversaw the final phases of the case, said, “There was no actual involvement by the defendants or the undercovers . . . in the activities of either Al Qaeda or the FARC.” Another judge saw as many problems with the statute as with the merits of the case. “Congress has passed a law that attempts to bind the world,” he said to me.

The investigation continues to be cited by the D.E.A. as an example of its national-security achievements. Since the narco-terrorism provision was passed, the D.E.A. has pursued dozens of cases that fit the broad description of crimes under the statute. The agency has claimed victories against Al Qaeda, Hezbollah, the Taliban, and the FARC and established the figure of the narco-terrorist as a preëminent threat to the United States.

With each purported success, the D.E.A. has lobbied Congress to increase its funding. In 2012, Michael Braun, who had served as the D.E.A.’s chief of operations, testified before Congress about the link between terrorists and drug traffickers: “Based on over thirty-seven years in the law-enforcement and security sectors, you can mark my word that they are most assuredly talking business and sharing lessons learned.”

That may well be true. In a number of regions, most notably Colombia and Afghanistan, there is convincing evidence that terrorists have worked with drug traffickers. But a close examination of the cases that the D.E.A. has pursued reveals a disturbing number that resemble that of the Malians. When these cases were prosecuted, the only links between drug trafficking and terrorism entered into evidence were provided by the D.E.A., using agents or informants who were paid hundreds of thousands of dollars to lure the targets into staged narco-terrorism conspiracies.

The D.E.A. strongly defends the effectiveness of such sting operations, claiming that they are a useful way to identify criminals who pose a threat to the United States before they act. Lou Milione, a senior official at the agency, told me, “One of the things the D.E.A. is kind of in the business of is almost all of our investigations are proactive.” But Russell Hanks, a former senior American diplomat, who got a firsthand look at some of the D.E.A.’s narco-terrorism targets during the time he served in West Africa, told me, “The D.E.A. provided everything these men needed to commit a crime, then said, ‘Wow, look what they did.’ ” He added, “This wasn’t terrorism—this was the manipulation of weak-minded people, in weak countries, in order to pad arrest records.”