If the French army and its allies are to keep al-Qaeda at bay in the desert of northern Mali they must stop them seizing the biggest prizes in the sea of white sand - the wells.
So this month a column of soldiers from France, Burkina Faso and Mali, in armored vehicles and pick-up trucks, churned towards a village north of Timbuktu where herders water camels and goats.
They were looking for signs of infiltration by militants who need water as much as the locals do and aim to convert villages to their ideology.
France uses drones, jets and helicopters in its Operation Barkhane mission to eliminate jihadist sanctuaries across five Sahel countries, but winning local support is key and that means face-to-face contact, soldiers said.
In days of patrolling with French forces around Timbuktu, villagers told Reuters they valued the multinational security presence and detested al-Qaeda. Villagers waved at the patrols at every stop.
"If MINUSMA (U.N. peacekeepers) and France leave we'll go back to Mauritania," said Mohamed Ould Aboubacar, 67, an elder who returned to the village last month from a refugee camp.
At this village, they ducked under a blanket that served as the door to the chief's tent and rested their rifles on a carpet. They asked Reuters not to name the village or the chief for security reasons.
An officer, who gave his name only as Lieutenant Nicolas, asked after the health of the chief, the village and its well and then turned to a key question: "Have you seen any strangers or foreigners come here?"
The chief said the only visitors were thirsty camel herders.
France launched its operation in Mali in January 2013 to drive out militants who had seized control of the north. They scattered the insurgents who continue to launch attacks, mostly in the Kidal region and near the porous borders of Algeria and Libya.
French forces say they face a dilemma. To hold back the militants in the area requires a long term commitment and Mali's army is not yet ready.
"The institutions exist in Mali. They just simply need to be made to work," said Colonel Jean-Michel Luccitti, the senior French commander in Mali. Mali began fresh talks with mostly Tuareg rebels in Algiers on Thursday aimed at ending decades of uprisings in the north. A successful outcome could free up Malian forces to counter al-Qaeda, Luccitti said.SHOW MORE