ISIS's funding sources: mafia-like taxes, drug cartel-like extortions

Washington

IN the last year, a once-obscure extremist group has overrun some of Iraq's major cities, seized control of oil wells, industries and banks, and emerged as the world's richest and most feared terrorist force.

Despite nine months and US$2.44 billion in US airstrikes against the fighters and their oil facilities and smuggling networks, the self-proclaimed Islamic State of Iraq and Syria (ISIS) has proven to be as resilient financially as it's been militarily.

The group that US President Barack Obama dismissed in January 2014 as a junior varsity team last year seized…