American Foreign Fighters and the Islamic State: Broad Challenges for Federal Law Enforcement
Jerome P. Bjelopera, Specialist in Organized Crime and Terrorism (firstname.lastname@example.org, 7-0622)
September 19, 2014 (IN10154)
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 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.
are American citizens, legal permanent residents, or aliens who radicalized in the
United States and plotted to or traveled abroad to join a foreign terrorist group.
There is scant publicly available information on Americans fighting for the Islamic State. However, the
Islamic State and its American acolytes may conceivably present at least three broad challenges for
domestic law enforcement. These challenges involve handling:
The Departed. A few Americans, often described as foreign fighters, have left the United States
to fight for the Islamic State. About 100 people from the United States have joined factions—not
just the Islamic State—fighting in the Syrian civil war.
The Returned. These are American foreign fighters with terrorist training and/or battlefield
experience who may come back to the United States, where they can potentially plan and execute
attacks at home. There have been no public reports of Americans (or others) who fought with the
Islamic State coming back to the United States and conspiring to commit acts of terrorism. This
challenge for U.S. law enforcement also potentially includes fighters who radicalized in and
originated from other countries —particularly Western nations—and may enter the United States
when done fighting abroad.
The Inspired. The fighting in Syria and Iraq has spawned propaganda that may stir some
Americans to plot attacks at home without ever leaving to fight abroad. Promoting the cause—
propaganda—is central to terrorism. IS members appear adept at harnessing social media to
spread their message, among other means. There have been reports that the Islamic State has
an American helping to organize its social media output. The group has been described as
"extremely tech- and media savvy," dispersing varied propaganda materials; and while much of
this work has been geared at drawing recruits into the fight in Syria and Iraq, it may also inspire
people in the United States to radicalize and strike at home without venturing abroad.
Responding to the Challenges
It seems that the domestic threat potentially presented by IS—the departed, the returned, and the
inspired—largely requires identifying individuals who pose a danger and preempting their attempts to
harm the homeland. A number of important federal identification and preemption efforts in the
counterterrorism arena are described below.
Identifying Potential Terrorists
The federal government's terrorist watchlisting process plays a key role in tracking people suspected of
having ties to IS. When federal law enforcement or intelligence agencies identify someone known or
reasonably suspected of terrorism, they are required to share that information to create a federal
consolidated watchlist of known or suspected terrorists. The watchlist supports "the ability of front line
screening agencies to positively identify known or suspected terrorists trying to obtain visas, enter the
country, board aircraft.... "
Preempting Potential Terrorists
Preemption of possible IS terrorist activity by U.S. law enforcement can be broadly described in terms
Interdiction. This involves—among other things—stopping a suspected terrorist from entering
the United States. For example, within DHS, components such as Customs and Border Protection
draw on information from the federal government's consolidated terrorist watchlist in intelligencedriven, layered screening geared toward mitigating the risk posed by travelers destined for the
United States. DHS Secretary Jeh Johnson has broadly alluded to U.S. coordination with allies on
foreign fighters. In an August 29, 2014 press release, he noted:
This government, in close collaboration with our international partners, has ... taken a series
of steps to track foreign fighters who travel in and out of Syria, and we are contemplating
additional security measures concerning foreign fighters. Some of the security measures will
be visible to the public and some understandably will be unseen.
Johnson has also mentioned enhanced screening at select overseas airports.
Investigation largely focuses on Joint Terrorism Task Forces (JTTFs) led by the Federal Bureau
of Investigation (FBI). They play the chief role in coordinating federal counterterrorism cases
across the United States, bringing together federal, state, and local participants in the process.
JTTFs have been involved in stopping individuals trying to leave the United States to fight with
the Islamic State. NCTC Director Olsen has noted that the FBI has arrested "more than a half a
dozen" such individuals.
Countering Violent Extremism. Thwarting terrorist plotters also involves the intricacies of
radicalization—especially determining when individuals move from radical activity involving First
Amendment-protected behavior to violent extremism. Much of the federal work in this area
includes outreach to local communities. Regarding the Islamic State, the FBI, DHS, and NCTC are
striving to understand the motivations driving people to radicalize and join terrorist groups in
Syria. Also, DHS and NCTC provide information to U.S. community groups about the recruitment
efforts of violent extremist groups based in Syria and Iraq. Finally, largely in response to the
Islamic State, DOJ announced a pilot program "in cities across the country to bring together
community representatives, public safety officials and religious leaders to counter violent
extremism." DOJ (and presumably the FBI) will partner with the White House, DHS, and NCTC in