For example, Baghdad provides about $130 million every month to pay all its workers in Mosul, according to the head of the Nineveh provincial council’s finance committee, who was forced to flee when the Islamic State took over. We can estimate that the Iraqi treasury has paid over $1 billion to these workers since the city fell last June.
The official financial system has been down since the jihadist militia seized control of the banks, so department emissaries are sent into Iraqi or Kurdish territory. They collect the salary money and return to disburse it.

This regular shuttle for trusted individuals has become routine in some places, even on the front lines. Referring to such practices, one Iraqi officer controlling a military checkpoint outside of Falluja recently noted, “There is a kind of strange coexistence between ISIS and the government authorities.”

Evidently, the Islamic State generates significant income by skimming off the top of this cash trafficking.