The Unique Counterterrorism Challenges Presented by Homegrown Violent Extremism

Even as the Islamic State faces battlefield defeat, first in Mosul and now in Raqqa, the threat of Homegrown Violent Extremism in on the rise. In the words of former Director of the National Counterterrorism Center, Matthew Olsen, said there is a "very significant chance" homegrown terrorist attacks will be carried out in the United States over the next couple of years. Both Islamic State and al Qaeda leaders have called for affiliates to carry out attacks in their home countries, and have even published guides, offering advice on how to effectively target civilians. Returning foreign terrorist fighters (FTFs) have only exacerbated this phenomenon. Today there are open investigations on about 1,000 potential homegrown violent extremists (HVEs) in all 50 states across the United States. Around the world, HVEs present not only pressing security threats but also a series of unique challenges to law enforcement and intelligence agencies.

Consider, for example, the long-effective tool of tracking the travel patterns of suspected terrorists and their associates. That remains an effective tool in some cases, especially the increasingly rare cases of foreign terrorist travelers. But the increasing threat of HVE terrorism rarely relies on foreign travel. According to a Department of Homeland Security (DHS) report, "most foreign-born, U.S.-based violent extremists likely radicalized several years after their entry to the United States." DHS's findings echo a U.S. House Homeland Security Committee December 2016 report, which concluded that "the United States faces its highest Islamist terror threat environment since 9/11, and much of the threat now stems from individuals who have been radicalized at home." Thus, even the strictest immigration policies fail to address this issue, because radicalization happens here.

But the most prominent challenge HVEs present to investigators comes in the area of combating terror finance. Once an individual or small cell radicalizes and decides to carry out a terrorist attack, there are several ways they may fund their attack. In contrast to the highly sophisticated attacks of September 11th, which cost about $500,000 and took years of planning, lone offender and small group attacks can be carried out quickly, with minimal funding and preparation.

Lone offender and small terror cells can minimize costs for attacks because they have few members to train and equip, rely on simple weapons such as knives, and in contrast to larger terrorist organizations, they are not subject to the high and indirect costs of developing and maintaining terrorist organizations.

Due to the relatively low cost of attacks, lone offenders and small cells often self-fund their attacks. Self-funding may include using one's own salary, receiving support from family and friends, engaging in criminal activities, or taking advantage of various types of legal financial loans. Though less common, some lone offenders and small cells with ties to larger terrorist organizations receive external monetary support for attacks.

In one case, Mohammed Merah, who carried out a series of shootings in France in 2012, relied heavily on criminal activities, including robbery and drug trafficking, to finance his attacks. Merah earned $58,000 as a drug courier between Spain and France, and was heavily involved in an established criminal network in France. In addition to the money he earned from crime, he received some financial support from family members and government welfare payments.

Transferring money is particularly important for lone offenders and small cells that receive external funding from larger terrorist organizations. The U.N. Security Council reported in August that "despite military pressure and falling revenues, the ISIL core continues to send funds to its affiliates worldwide, using a combination of money or value transfer services and the transport of bulk cash." The UN report added that "ISIL core has also sent money to places where it does not have affiliates, which according to a Member State assessment, is an attempt to prepare for its eventual military defeat" in Syria and Iraq. Evidently, not only is ISIL preparing to move funds to its other provinces, it is also sending funds to locations where newly inspired followers or returning foreign fighters can use such funds for attacks at home.

While battlefield defeats in Syria and Iraq may mean a weaker ISIL core, lone offenders and small cell attacks will continue to challenge counterterrorism authorities' traditional counter-terror finance tools. Since small scale attacks may be carried out relatively quickly and with minimal preparation, authorities are left with little lag time to run an effective investigation. Furthermore, authorities may not be able to follow key tripwires, such as the travel, communications and financial trails of individuals involved in smaller plots.

Homegrown terrorism may often be less sophisticated than terrorism carried out by organized groups, but it is likely to be more frequent and, as recent attacks around the world have underscored, painfully successful. Military success against the Islamic State will almost certainly not lead to a drop in terrorism in the West. Addressing the challenges HVE plots present for law enforcement and intelligence officials should be a top priority now that Mosul and Raqqa have been liberated.