"There are market forces that explain why jihadists succeed in civil wars— when so many other types of groups look like they should have traction on the ground— don't," says Aisha Ahmad. "In order for your movement to succeed, and you have enough money to buy the bullets and feed your foot soldiers. And so there is a logic that's taking place behind the scenes that explains why these seemingly illogical movements rise to power."

"Where jihadists do well is in a vacuum in the political chaos of a failed state," says Ahmad.

Ahamd is the author of Jihad & Co.: Black Markets and Islamist Power, which looks at financing through two sets of case studies: the Afghanistan/Pakistan cluster and Somalia.

"When we look at these sorts of war economies, we need to have a holistic understanding of the kind of businesses that take place— which span both licit and illicit activities," says Ahmad.

Ahmad is an assistant professor at the University of Toronto, a senior fellow at Massey College, and the co-director of the Islam and Global Affairs Initiative and a senior researcher of the Global Justice Lab at the Munk School of Global Affairs.