Reporting from Johannesburg, South Africa#8212; When a small group of Nigerian Islamist militants attacked two police stations and killed an officer, government security forces moved in swiftly, announcing they had crushed the revolt. Ten months later, the militants attacked two more stations, slaying four officers. This time Nigerian security forces killed dozens of fighters, and the state police commissioner announced that it was just a matter of hours before [all] the militants will be flushed out. More than a decade later, that hasn't happened. Instead, the northern Nigerian group known as Boko Haram, in response to the government crackdown, has grown exponentially and is...