In Nigeria, Cameroon, Chad, and Niger, the extremist group Boko Haram – famous for its kidnapping of 276 school girls in 2014 – has inflicted thousands of casualties with suicide bombings and assaults on civilians. In Kenya, the Somali group Al-Shabaab has carried out two major attacks, on Nairobi’s Westgate shopping mall in 2013 and on Garissa University in 2015, as well as many smaller acts of terror.