American Foreign Fighters and the Islamic State: Broad Challenges for Federal Law Enforcement [September 19, 2014] [open pdf - 61KB]
"The Department of Homeland Security (DHS) has assessed that the terrorist group known as the Islamic State (IS, previously referred to as ISIS or ISIL) currently poses no specific or credible threat to the homeland. The Director of the National Counterterrorism Center (NCTC), Matthew G. Olsen, has also noted that, 'any threat to the U.S. homeland from these types of extremists is likely to be limited in scope and scale,' perhaps involving individuals acting without specific IS direction. In this vein, policy makers continue to voice concerns about American IS fighters who may leave Syria or Iraq, return to the United States, and strike targets on their own at home. This CRS [Congressional Research Service] Insight offers a framework for considering the challenges to domestic security posed by American IS fighters and outlines some of the ways that U.S. law enforcement responds to such challenges."
CRS Insight, IN10154