There has long been speculation about how Boko Haram and other terrorist organizations are funded. Some funding clearly comes [PDF] from criminal activity, with kidnapping particularly lucrative, and from bank robberies. Presumably, protection rackets also play a role. At some times and in some places, Boko Haram has been able to impose “taxes” on the local population. Boko Haram has also been involved in trading, especially in the Lake Chad Basin. Weapons—a major expense—appear often to come from government armories, sometimes because...