BURAO, SOMALILANDSo many died at once “it was like they were poisoned,” said Rahma Hassan Mahmoud, a herder in Somaliland, of the catastrophe that befell her 300 goats and sheep and 20 camels. After the last camel died, she and her family lived off milk from their neighbors, but with everyone else’s livestock dying, it wasn’t long before there wasn’t enough to go around.

The people of Rahma’s village pooled money to rent a truck. Fifty of them climbed in for an overnight drive to the city of Burao, in central Somaliland. Along the road, they passed clusters of domed huts made from gathered wood, plastic sheets, and draped cloths—makeshift settlements housing people who, like them, had lived off the land but