Gao — After French troops drove militants from towns at the edge of the Sahara in late January, locals looted the newly abandoned stucco palaces of "Cité du Cocaine"—Cocaine City.
It has been a tough couple of months for the traffickers of Gao, the desert trading outpost where this district of luxurious villas is located. The French military offensive that evicted Islamist militias also drove out drug smugglers who, according to security experts and Malian officials, enjoyed militant protection in their business of transporting Europe-bound drugs across the dunes and lava crags of the Sahara.
Gao and other areas in Mali's north remain a war zone. Islamist fighters have launched three major assaults since February in the heart of Gao, a town of 80,000 people where homes of mud brick, thatch or concrete block sprawl around crumbling whitewashed buildings of what was once colonial French West Africa.
Fighting destroyed municipal buildings and burned down the market that had rambled for blocks through the heart of the city. Three-fourths of the city's residents have yet to return, said Mayor Sadou Diallo, who flew back to Gao in February with French forces anxious to show Mali's government returning to the north.
Many of Gao's drug smugglers were members of northern Mali's Arab minority, whose forebears traded along centuries-old salt caravan routes. In about 2003, these traders began to transport cocaine through the ancient passages, as South American drug cartels sought to expand sales to Europe to offset flat demand in the U.S., according to the United Nations Office on Drugs and Crime.
Around the same time, a band of Islamist militants left their homeland of Algeria and found refuge in the difficult terrain outside Gao, where they pledged allegiance to Osama bin Laden and renamed themselves al Qaeda in the Islamic Maghreb. AQIM commander Mokhtar Belmokhtar married the daughter of a Malian Arab dignitary, elevating himself into a position of influence over cocaine traffickers, according to U.S. counterterrorism officials.
Islamist militias such as AQIM, which generated funds for guns and recruitment by kidnapping and ransoming Western hostages, profited from protection money and other proceeds of the drugs trade, according to security analysts.
During this era in the mid-2000s, Gao—remote, lightly governed and long known as a hub for black-market trade—became a staging post for cocaine traffickers. Newly successful businessmen began building homes in a neighborhood soon known as Cocaine City. Tall concrete and stucco villas redefined a stretch of the horizon, while builders trucked in TVs, satellite dishes and boxes of hand-painted tile to decorate the houses.
The outside world got a vivid glimpse of Gao's cocaine trade in 2009, in an episode local media dubbed "Air Cocaine." Malian prosecutors said Malian and European drug traffickers landed, in the desert near Gao, a 727 jet loaded with up to 10 tons of Colombian cocaine. When mechanical troubles kept the 727 from taking off, traffickers unloaded the cocaine and burned the jet, according to the criminal charges filed by the prosecutors.
By then, drug seizures and political turbulence already had begun to sap the drug trade in West Africa, according to U.N. drug officials. The flow of cocaine through West Africa to Europe peaked in 2007 at 47 tons. It dropped to 18 tons in 2010, the latest year for which the U.N. drug office has given estimates.
The reduced volume still represents $1.25 billion of cocaine crossing an impoverished region, the agency said. The sum dwarfs the security budgets of many West African nations and suggests at least one-tenth of the cocaine in Europe reaches the continent through West Africa, the agency estimates.
Not everybody has benefited. In March 2012, junior Malian military officers mutinied, overthrowing the civilian government in Bamako. They cited corruption and cocaine trafficking by their generals and elected leaders. A week later, AQIM and allied militias took control of Gao, and with it, control of the northern half of the country.
Gao residents said some of the Islamist militias were avid participants in the cocaine trade. "They said they came for religion. But when they came, we saw they came for trafficking," Mr. Diallo, the mayor of Gao, said of one Islamist militia, Nigeria-based Boko Haram.
One militia in particular, the Movement for Oneness and Jihad in West Africa, "quickly became a front for drug smugglers from Gao," Wolfram Lacher, a German expert on West Africa, wrote in a 2012 report for the Carnegie Endowment.
In January, the French intervention halted a southern advance by Islamist militias. As militia chiefs retreated, the residents of Cocaine City fled their mansions, residents said. Locals flooded in and stripped what was left, lugging away doors and toilets.
Remaining debris in the looted villas testifies to Cocaine City's fast times. Instruction manuals for satellite phones and widescreen TVs litter floors. In one home, stripped to its blue tile, hand-scrawled ledgers bear large sums recording building costs and other unspecified transactions.
Mali's new transitional administration says it is trying to flush supporters of the cocaine trade from the security services and government. In February, the government charged six Malians, including three former mayors from the region around Gao, with trafficking drugs, according to Alassane Diarra, a spokesman for Mali's Justice Ministry.
None of the six has been apprehended. Two wanted for alleged involvement in the Air Cocaine episode, including a former mayor, are moving freely in a village within a day's drive of Gao, according to Mr. Diarra and a military spokesman.
"There are problems," Mr. Diarra said to explain why no arrests had been made. "Among them, problems of security."
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