Malian army forces secure a road between Goundam and Timbuktu, northern Mali, on June 2, 2015, as part of a counterterrorism operation in the Sahel.

Malian army forces secure a road between Goundam and Timbuktu, northern Mali, on June 2, 2015, as part of a counterterrorism operation in the Sahel. Attacks by Islamist armed groups since 2015 have spread into central Mali, challenging the Malian army’s ability to secure territory and fostering the growth of ethnic self-defense groups.

© 2015 PHILIPPE DESMAZES/AFP/Getty Images.