In 2014, following the kidnapping of 230 teenage girls from the mainly Christian enclave of Chibok in northern Nigeria, World Watch Monitor asked the question: How does Boko Haram justify its actions?

A year later, The New York Times reports that the self-proclaimed Islamic State has “enshrined a theology of rape” in conquered regions of Iraq and Syria, “codifying sex slavery” and “using the practice as a recruiting tool”. (Boko Haram in April 2015 said it now identifies as the “Islamic State’s West Africa Province”.)