While international terrorism seems like the biggest threat to U.S. national security, domestic terrorism is also a law enforcement priority. However, its treatment by the U.S. government differs greatly from that of international terrorism: there is no centralized, public, official list of domestic terrorist organizations or sponsors. Tracking domestic terrorism falls primarily to the FBI, which defines it as “perpetrated by individuals and/or groups inspired by or associated with primarily U.S.-based movements that espouse extremist ideologies of a political, religious, social, racial, or environmental nature.”
The FBI does maintain a list of most wanted terrorists, people charged with federal crimes, and people it deems responsible for domestic terrorism. None of the individuals in the latter group, however, are actually charged with domestic terrorism, because no crime called domestic terrorism exists in U.S. law. Instead, someone is charged with murder, assault, or other violent crimes.
Notably, the FBI also periodically identifies what it calls threats (such as militia extremists plotting to overthrow the U.S. government) or homegrown violent extremists (people in the United States who have been radicalized but aren’t working with an FTO). The FBI coordinates a separate terrorist watch list, comprised of people suspected of involvement in terrorist activities or of providing aid to terrorists also exists, to which multiple government agencies contribute. The famous “no fly list” is derived from this watch list.
Terrorist designations determine the consequences of committing terrorist acts.
The difficulty in defining domestic terrorism does not only limit who gets designated as a threat, it also affects the legal consequences for committing acts of terror in the United States. Under U.S. law, a perpetrator can be explicitly charged with a crime relating to international terrorism but not domestic acts. Even though U.S. government agencies, and laws like the Patriot Act, offer definitions of terrorism, those definitions haven’t been translated into specific crimes with which a prosecutor can charge someone.
What this means is that if an investigation into a violent act reveals a political motive and links to an FTO, the perpetrator can be labeled a terrorist and prosecuted under those specific laws, which allow, in part, for much longer terms in prison. This was the case with the 2017 van attack in New York City that killed eight people, because the perpetrator declared allegiance to the self-proclaimed Islamic State.
But for domestic perpetrators with no links to FTOs and whose ideology is sometimes harder to prove, the consequences are different. For example, someone like the perpetrator of the 2017 Las Vegas shooting, which killed fifty-eight and injured over five hundred, who had no political motive that the FBI could find, would have been charged with murder and other crimes—not domestic terrorism—if he had not died by suicide during the shooting.
Lone Wolf attackers: are they terrorists?
Another common term in debates over terrorism is lone wolf. The term is used to describe attackers who seem not to be officially unconnected to a terrorist organization (even if they were possibly inspired by one), and who seem to independently commit acts of violence—for example, the police used the term to describe the Las Vegas shooter. It’s used to distinguish people and events like the Las Vegas shooting from those like the 9/11 attacks, several sophisticated, well-funded, organized terrorist attacks carried out simultaneously by multiple people.
Lone wolf is a controversial term among experts for several reasons. Some find it misleading, arguing that people have to be radicalized somewhere, by something or someone, and therefore can never be said to be acting entirely alone. If an attacker is inspired by propaganda, such as explicit demands by the Islamic State for more lone wolf attacks, can they really be considered lone wolves? Some experts also assert that the term lone wolf is glamorizing and should thus be avoided.
The term is still frequently used, including by law enforcement and elected officials, and is important to know. The FBI investigates potential lone wolf attackers, whom it considers a top U.S. national security threat. According to researchers, in the United States, lone wolves make up 6 percent of terrorists but are responsible for 25 percent of attacks, and their attacks tend to be harder to predict and prevent given their more isolated nature.
Who counts as a terrorist and what counts as terrorism is a debate that remains unresolved.
As questions over what counts as terrorism and who counts as a terrorist persist, it’s important to remember that describing something as terrorism doesn’t necessarily make it so legally. Eagerness to precisely define or categorize an attack or attacker in the wake of an event leads to confusion and debate over what qualifies as terrorism, especially since 9/11, which spawned a sprawling U.S. counterterrorism infrastructure that has focused its attention and resources on international terrorism, despite other genuine, deadly threats.