The United States on Monday imposed sanctions on what it said was a network of five Islamic State financial facilitators working across Indonesia, Syria and Turkey in support of members of the extremist jihadist group in Syria. The U.S. Treasury Department in a statement accused those designated of playing a key role in facilitating the travel of extremists to Syria and other areas where Islamic State operates, and of conducting financial transfers to support the group's efforts in Syria-based displaced persons camps.
Some ISIS chapters can be fought using military force, but much of its clandestine activity can only be fought using economic warfare, or sometimes cyber warfare.