What’s made IS one of the richest terrorist armies ever?
Clip: 11/19/2015 | 8m 50s
How does the Islamic State militant group make money to fund its operations? A key source is oil extraction, which has helped make the group one of the richest terrorist armies in history. Economics correspondent Paul Solman takes a look at the Islamic State’s revenue sources, while William Brangham learns more from Cam Simpson of Bloomberg Businessweek.
Problems Playing Video? | Closed Captioning