In order to provide a definition of lone wolf terrorism, we first must have a definition of terrorism in general. The definitional problem, however, has plagued terrorism studies and counterterrorism policies for a long time. Different governments, institutions, scholars, and others all have their own criteria when it comes to deciding how to label violence that is linked to political, religious, social, and other causes. One study found more than one hundred different proposed definitions of terrorism, and that was only for the period from 1936 to 1981.1 There have undoubtedly been many other definitions of terrorism offered in the post-9/11 world, with seemingly everybody now writing or talking about terrorism.

The US State Department itself could not decide from one year to the next how to define terrorism. For example, in its 2003 report on global terrorism, the State Department defined terrorism as “premeditated, politically motivated violence perpetrated against non-combatant targets by sub-national groups or clandestine agents, usually intended to influence an audience.”² The next year, however, they deleted the phrase “usually intended to influence an audience” without any explanation.³ It has remained deleted in all subsequent reports.

The confusion over definitions of terrorism could also be seen in the interpretation of the term “non-combatant.” In its 2003 report, the State Department wrote that noncombatants were “in addition to civilians, military personnel who at the time of the incident are unarmed and/or not on duty.”⁴ That would mean any soldiers or other military personnel located anywhere in the world and not carrying a weapon or on duty would be considered to be noncombatants. Violence against them would therefore be interpreted as an act of terrorism. If, however, they are carrying arms or are on duty, then no matter where the incident occurs, violence against them would not be considered terrorism. Yet, in its 2004 report, the State Department reversed itself and wrote that “the term ‘non-combatant’…is interpreted to mean, in addition to civilians, military personnel (whether or not armed or on duty) who are not deployed in a war zone or a war-like setting.”5 Now the definition meant that soldiers or other military personnel would be considered to be noncombatants even if they were armed or on duty, provided they were in a country or area that was not considered to be a “war zone” or “war-like setting.” The State Department has kept that interpretation in subsequent reports.

The changing meaning of “non-combatant” in the State Department's definition of terrorism was probably due to the wars in Iraq and Afghanistan. The Iraqi war, in particular, which began in 2003, caused considerable confusion within the US government about how to portray those who were fighting against the United States and its allies. At first, those who committed bombings and other violent acts in Iraq against US troops, Iraqi security forces, civilians, and others were described by the US government and most media outlets as “terrorists.”⁶ Eventually, though, the perpetrators of these attacks were described as “insurgents” or “militants,” with the term insurgents usually reserved for Sunni extremists and the term militants usually used to refer to Shiite extremists.

The FBI also struggled with its definition of terrorism, changing it from one year to the next as it tried to decide if a single individual (lone wolf) should be considered a terrorist. In 1994, the FBI defined domestic terrorism as “the unlawful use of force or violence, committed by a group(s) or two or more individuals, against persons or property to intimidate or coerce a government, the civilian population, or any segment thereof, in furtherance of political or social objectives.”⁷ This definition excluded the single individual, such as Theodore Kaczynski, the infamous Unabomber, who had yet to be caught and was still sending package bombs to victims. In fact, in December 1994 an advertising executive, Thomas Mosser, was killed when he opened a package bomb that was sent by Kaczynski to his New Jersey home. The FBI reported zero incidents of domestic terrorism for that year.8 The next year, the words “group(s) or two or more individuals” was replaced with “groups or individuals.”⁹ This seemed to include lone wolves, since the plural “individuals” could be interpreted to mean different individuals perpetrating different attacks rather than multiple individuals teaming up to perpetrate an attack. Finally, in 1999, the wording was again changed, this time to “a group or individual,” which left no doubt that a lone wolf could be considered a terrorist.¹⁰

However, the FBI noted in its 1999 report that it still did not view Kaczynski's activities or those of Amil Kanzi, who killed two CIA employees and wounded three others in a shooting spree outside the agency's headquarters in Langley, Virginia, in January 1993, as constituting acts of terrorism:

While views vary widely concerning whether Theodore Kaczynski (the UNABOMBER) and Amil Kanzi…are terrorists, the FBI does not classify the acts committed by these individuals as incidents of terrorism. When the series of deadly bombings perpetrated by the “UNABOMBER” began in the 1970s, the subject's motivations were unclear. It was not known, for example, whether, the subject's targets were chosen randomly or as part of some personal vendetta. Due to the lack of information regarding the subject's motivation, the FBI investigated the case as a criminal, rather than as a terrorism, matter.

Although an attack on vehicles outside the entrance of a U.S. Government facility may raise the specter of terrorist intent, FBI investigation into the January 1993 shooting outside CIA headquarters did not support speculation that the attack was an act of terrorism. Amil Kanzi, the individual ultimately identified as the lone assailant in the shooting, was determined by the FBI to be acting on personal, rather than ideological, motivations.¹¹

The FBI never indicated in subsequent years whether it had changed its view of Kaczynski and Kanzi as not being terrorists. Yet both individuals were indeed motivated by political objectives to some degree. Kaczynski demanded that a rambling, thirty-five-thousand-word manifesto calling for a revolution against the industrial-technological society be published in the New York Times or the Washington Post or he would continue to send package bombs. (It was published in September 1995 in the Washington Post, with the New York Times sharing the printing cost.) When one perpetrates violence in the name of a revolution, whatever type of revolution that may be, it would seem to qualify as a political or ideological motivation. In the case of Kanzi, his violent actions were based on his desire to protest American foreign policy, which he believed was harming Muslims around the world. He told FBI special agent Brad Garrett on a flight from Pakistan to the United States (he had fled the country after the shootings and was arrested in Pakistan in 1997) that he wanted to “teach a lesson” to the US government. According to Garrett, Kanzi thought his actions would change US policies. “It was almost illogic logic,” Garrett told a reporter. “It wasn't personal. It wasn't like hating individuals. It was more institutional.”12

The issue of motivations again came up in the case of an Egyptian immigrant, Hesham Mohamed Hadayet, who shot and killed two people at an Israeli El Al Airlines ticket counter at Los Angeles International Airport on July 4, 2002. After several months of investigation, the FBI determined that Hadayet, who was killed by an El Al security guard at the airport, acted alone and that his violence constituted an act of terrorism. Although Hadayet was depressed over personal issues, including a failing business, he targeted the El Al ticket counter due to his anger over Israel's treatment of Palestinians. He had also told people close to him that he believed in jihad and in the targeting of innocent civilians. “The barrier to calling it a terrorist event earlier than now was that we did not know his motivations,” a Los Angeles FBI spokesman said. “We think we have a very good handle on that now.”¹³

What, though, if somebody's motivation for violence is indeed personal, with no political, ideological, or religious objective in mind? Are there circumstances in which those acts of violence can be considered terrorism? One example would be the hijacking of a plane for money. Imagine a lone wolf or a group of individuals hijacking a plane and demanding a large sum of money in exchange for the lives of the passengers and crew. There is no political or other motivation except monetary gain. The effect on government and society, however, would be the same as if the motivation and objective were political, ideological, or religious. The government would still have to initiate negotiations with the hijacker or hijackers, launch a potential hostage-rescue operation, increase security at airports, and take other measures to reduce the risk of future hijackings. There would be fear among the public concerning the safety of air travel, as other criminals, or even the same group, might commit additional hijackings. There would also be widespread media coverage and statements by high-level government officials, all adding to the crisis atmosphere of the hijacking. Under virtually all definitions of terrorism, this would not qualify as a terrorist incident, even though it has the same effects as a “terrorist” attack. And if the group simply stated that their action was done in the name of some cause rather than for monetary gain, there would be little debate as to whether the incident qualifies as a terrorist event.

Monetary gain, in fact, was the motive for the first major midair plane bombing in the United States. John Gilbert Graham (who was mentioned in the introduction and discussed in further detail in chapter 2) put several sticks of dynamite and a timer in his mother's luggage before she boarded a United Airlines flight out of Denver on November 1, 1955. Graham was hoping to collect a $37,500 insurance policy on her life. Forty-four people, including Graham's mother, were killed in the bombing. President Dwight Eisenhower, as was the case for most Americans, expressed outrage at this new form of violence. There were also reactions from Congress, which soon afterward passed a bill that established the death penalty for anyone convicted of causing loss of life by damaging an airplane, bus, or commercial vehicle. (An existing statute covered the sabotage of trains).

Graham was executed in 1957 under Colorado law for murder. The FBI and the Civil Aviation Administration began conducting studies on measures that might be taken to detect explosives in luggage. There was also an increase in bomb threats to US airlines following the Graham attack. Thus, in many respects, there was little difference in government and societal reactions to the Graham bombing, which had a purely financial motive, than there would have been had Graham or an extremist group perpetrated the violence in the name of some political, social, or religious cause.14

The requirement in many definitions of terrorism that there be a political, social, or religious objective associated with the act of violence would also exclude those terrorists who suffer from various types of mental illness and commit their violence for no apparent reason beyond their own psychological problems. If Kaczynski, the Unabomber, did not have as his motive a “revolution” against the technological-industrial society but rather sent the package bombs and made threats for no apparent reason, it would still be “terrorism,” based on the effect it had on the United States. The Unabomber's activities caused fear and anxiety among the public, frustrated the government in its search for the perpetrator, and led to changes in the way packages were allowed to be sent through the mail.

There are many other aspects of definitions of terrorism that could be challenged, such as the “innocent victims” or “non-combatant” phrases used by many observers to denote a terrorist attack. As pointed out earlier, the US State Department changed its interpretation of who qualified as a noncombatant. Several scholarly and other definitions of terrorism over the years have used the innocent-victims distinction, yet terrorists oftentimes do not recognize that classification. As noted in chapter 2, a French anarchist, Émile Henry, coined a phrase in the late-nineteenth century that many terrorists still use today. Henry hurled a homemade bomb (or in today's jargon, an IED) into a crowded café in Paris in 1894 to avenge the recent execution of a fellow anarchist. The bombing resulted in several injuries and one death. When the judges at his trial expressed bewilderment at the crime, pointing out that most of the victims were small shopkeepers, clerks, and workers—people who were innocent of any wrongdoing—Henry simply replied, “There are no innocent bourgeois.”15 That was basically the same view of Faisal Shahzad, the man who placed a bomb that failed to detonate in Times Square in New York City in May 2010. During submission of his guilty plea, the judge asked him if he was aware that there were innocent people walking around Times Square that night who could have been killed by his bomb. Shahzad replied, “Well, the people select the government; we consider them all the same.”¹⁶

So how, then, should we define terrorism? As I crafted the wording, I focused on what I thought to be the main challenge in creating a meaningful definition of terrorism—namely, how to account for those tactics that appear to be terrorism but are not perpetrated by a “terrorist” or do not have the same motives as those of a terrorist yet have virtually the same impact on government and society as a “terrorist” act. An adequate definition of terrorism also needs to exclude violence that may occur during the course of a protest, demonstration, popular uprising, or guerrilla insurgency against a government's troops. Taking all of these factors into account requires a rather long-worded definition of terrorism:

Terrorism is the use or threat of violence or nonviolent sabotage, including cyber attacks, against government, society, business, the military (when the military is not an occupying force or involved in a war, insurgency, or state of hostilities), or any other target, by individual(s) or group(s) (but not including actions taken during popular uprisings, riots, or violent protests), to further a political, social, religious, financial, or other related goal, or, when not having such an objective, nevertheless has the same effect, or potential effect, upon government, society, business, or the military in terms of creating fear and/or disrupting daily life and/or causing government, society, business, or the military to react with heightened security and/or other responses.

A definition of lone wolf terrorism would be exactly the same as the above general definition of terrorism, but to qualify as a lone wolf, an individual would have to be working alone or have just minimal assistance from one or two other people (such as Timothy McVeigh receiving assistance from Terry Nichols in preparing the bomb that was used to blow up the federal building in Oklahoma City). Therefore, lone wolf terrorism can be defined as follows:

Lone wolf terrorism is the use or threat of violence or nonviolent sabotage, including cyber attacks, against government, society, business, the military (when the military is not an occupying force or involved in a war, insurgency, or state of hostilities), or any other target, by an individual acting alone or with minimal support from one or two other people (but not including actions taken during popular uprisings, riots, or violent protests), to further a political, social, religious, financial, or other related goal, or, when not having such an objective, nevertheless has the same effect, or potential effect, upon government, society, business, or the military in terms of creating fear and/or disrupting daily life and/or causing government, society, business, or the military to react with heightened security and/or other responses.

Any definition of terrorism, whether it is lone wolf terrorism or terrorism in general, will naturally have many gray areas. For example, from the definition of both general and lone wolf terrorism, I have chosen to exclude all violent actions taken during a protest, demonstration, or mass uprising. Yet one could make the case that somebody throwing a bomb, shooting a gun, or setting fire to a building during a mass demonstration is perpetrating an act of terrorism. To do so, though, would seem to open up the floodgates on incidents of terrorism, as virtually every violent action occurring during a demonstration or protest would be counted as a terrorist act. That is why definitions of terrorism are problematic and will always be open to debate.