A mourner leaves a message at a makeshift memorial a day after a van struck multiple people along a major intersection in north Toronto, Canada.Carlo Allegri / Reuters

Two mass murders took place within 48 hours this week. Both attackers were adherents of extremist ideologies. Both terrorized people. But one of these two attacks was clearly terrorism, and one was apparently not. What’s the difference?

Early Sunday morning, Travis Reinking walked into a Tennessee Waffle House wearing nothing but a jacket and started shooting, killing four and wounding several more. Early reporting indicates that Reinking had a history of apparent mental illness. But Reinking also identified himself as a sovereign citizen, an antigovernment movement associated with more than 100 acts of violence and dozens of deaths over the last decade and a half.

On Monday afternoon, 25-year-old Alek Minassian drove a rented van into dozens of Toronto pedestrians, killing 10 and wounding 13. It soon emerged that he was an adherent of the so-called “incel” movement, short for “involuntarily celibate,” a term co-opted by online adherents of an anti-woman ideology whose primary grievance is that women aren’t having sex with them. Minassian posted on Facebook moments before starting his rampage:

Private (Recruit) Minassian Infantry 00010, wishing to speak to Sgt 4chan please. C23249161. The Incel Rebellion has already begun! We will overthrow all the Chads and Stacys! All hail the Supreme Gentleman Elliot Rodger.

(All signs point to the post being authentic, but the reference to 4chan, the origin point of many online hoaxes, has been a red flag for some analysts.)

The place to start, in distinguishing between these attacks, is by defining terrorism. The word has been politicized like few others, used as a rhetorical tool to demonize society’s villains du jour. Even within academic and policy circles, there is dispute over its precise meaning. Within the U.S. government, terrorism is a word usually, and improperly, reserved for jihadist extremists, due in part to the political proclivities of the moment and the statutory definition of terrorism, which is for the most part restricted to specifically designated foreign-terrorist organizations.

For most who deal with the issue day in and day out, though, terrorism is public violence to advance a political, social, or religious cause or ideology. Some variation remains as far as the details (many people distinguish between military and civilian targets, for instance, or stipulate that the perpetrator be a nonstate actor), but this broad definition has been widely adopted in the almost 17 years since September 11 and the launch of the Global War on … well, you know.

In the Waffle House shooting, no information has so far emerged to suggest that the attack was intended to advance an ideology, even though the perpetrator was apparently an extremist adherent. The investigation, of course, is still in its early days. Sometimes it takes years of investigation to gather enough information to make a correct assessment. But some details of the attack (the attacker’s nudity, the timing, and choice of target) seem to point in a different direction. Reinking’s involvement in sovereign citizenry may have contributed to his violent tendencies, but there is nothing to suggest his attack was meant to be instrumental.

The Toronto attack presents a very different situation. The driver posted a statement moments before the attack began. Although too brief to be considered a manifesto, that statement nevertheless contains all the elements necessary to deem this terrorism.

Minassian’s post announces that the revolution has begun, in the form of his attack, an extremely typical terrorist motive. Timothy McVeigh was very clear that this was the goal of the 1995 Oklahoma City bombing, which is universally considered terrorism. Minassian’s ideology may be stupid or pathetic, but most terrorist ideologies are when examined closely enough. Stupidity and pathos are not disqualifying.

Furthermore, beneath Minassian’s ideological jargon (which could easily be mistaken for lunatic ramblings), the statement contains all the standard components of extremist belief, including an in-group (the group to which an extremist belongs, in this case, the sexually deprived incels) and an out-group (the group targeted by the extremist group, in this case, Chads and Stacys, which translates from incelspeak as people with normal sex lives).

The statement closes by referencing an incel extremist ideologue, Elliot Rodger, who penned a 141-page, 100,000-word manifesto about his sexual deprivation and the evils of women before embarking on his own violent spree in 2014, leaving six victims dead and more than a dozen wounded. Minassian’s statement may be brief, but it incorporates complexity from other sources.

A Facebook post that said “The ISIS Rebellion has already begun! We will overthrow all the kaffir! All hail Abu Bakr al Baghdadi!” would have produced a very different conversation. For some people, terrorism can only be carried out by certain groups, such as Muslims. For others, disturbingly, hate and violence toward women is somehow a less important crime.

This is the soft bigotry in selective outrage. After I tweeted my view that the attack was terrorism, a number of people responded negatively, referring to Minassian dismissively as someone who was “simply” mentally ill or “an obviously troubled guy.” Some cited Minassian’s alleged autism, despite the fact autism is not credibly linked to violence.

Even if mental-health issues contributed to the attack, that doesn’t mean it wasn’t terrorism. While there are rare situations in which someone can be so unmoored from reality that their stated motive is irrelevant, there is little to suggest that is the case here (again, with the important caveat that the investigation remains in its early stages). The definition of terrorism does not contain an exemption for mental illness. In some cases, where the perpetrator is profoundly incapable of understanding the context of the act, it’s possible to mount an argument that a particular incident should be excluded. But such cases are extraordinarily rare.

This week’s bloodshed was certainly not the beginning of this debate. Recent years have seen a significant number of ambiguous mass killings, including shootings and vehicular attacks likely emulating ISIS and al Qaeda tactics. In many of these cases, the question of terrorism was unclear, or only became clear over time.

In 2012, a white-supremacist skinhead massacred six people at a Sikh Temple in Wisconsin. He was clearly an extremist, but he left no clues or insights into the motive for his attack. It is probably correct to classify this incident as terrorism or a hate crime. But it’s difficult to be definitive, because he didn’t tell us in explicit terms. Terrorism is about sending messages, and if there’s no clear message, we are left with questions.

Some attacks raise questions that cannot be answered in the heat of a breaking-news cycle. In the case of the San Bernardino shooting, which killed 14 in 2015, it took weeks for elements of the attack to become clear. The initial shooting was carried out in the suspects’ workplace and targeted their coworkers, which is extremely abnormal for a terrorist attack. Their subsequent plans were foiled by law enforcement before they could be carried out. It took months to resolve whether or not Tashfeen Malik, one of the husband-wife shooters, had posted a pledge of allegiance to ISIS on Facebook around the time of the attack. It turned out that she had, and despite the unusual features of the attack, it is now considered terrorism.

Similarly, after the 2016 Pulse nightclub shooting, a number of stories emerged to suggest that Omar Mateen may have been motivated to attack the gay club by internal conflicts about his sexuality. Here, too, it became clear over time that his motive was traditionally terrorist. Mateen may have had personal issues that transcended his extremism, but it is now clear the attack was terrorism.

In contrast, a 2014 hostage-taking attack in Australia was explicitly carried out in the name of terrorism, but the facts of the case raised a lot of questions. The attacker had a history of bizarre practices and sexual assault, and he had suddenly taken an interest in ISIS just days before the attack, converting to Sunni Islam out of nowhere and declaring his allegiance in a sparse online posting. During the standoff, one of his demands was that authorities provide an ISIS flag for him to display in the window, because he had obtained the wrong one. ISIS later adopted the attack, and it is generally considered terrorism today despite these anomalies.

The involvement of a terrorist organization like ISIS is sufficient but not necessary to categorize an attack as terrorism. After Dylann Roof killed nine people in Charleston in 2015, he left a manifesto that clearly outlined his desire to advance a white-nationalist ideology, and reiterated his intent with additional writings while in prison. That attack met the definition of terrorism. Last year’s vehicular homicide of Heather Heyer at the Unite the Right rally in Charlottesville, Virginia, was also unmistakably political, carried out as it was by a white-nationalist protestor against a counter-protestor during a political clash. This, too, was terrorism.

But many cases remain unresolved, and some may never be clearly categorized. The serial bombings in Austin, Texas, earlier this year were particularly controversial, because bombings as a tactic are so closely associated with terrorism, and because some (but not all) of the bomber’s targets were found in minority neighborhoods. As with Wade Page, the bomber left no clear clues about his motive. He was reportedly associated with a survivalist movement (as was Newtown shooter Adam Lanza). But survivalism in and of itself is almost never a motive for terrorism, although survivalist practices are often adopted by adherents of other extremist ideologies.

There are many more examples, within just the last few years, but these suffice to make some things clear. First, it is possible to define terrorism using reasonably objective criteria that minimize ambiguity. Second, it will not always be clear in the immediate aftermath whether or not an attack is terrorism. It takes time to uncover what lies behind an attack. Third, while we can minimize ambiguity, we can’t always eliminate it. Some cases, like the Wisconsin temple attack, will never be cleanly resolved.

It’s fair to ask why it matters so much. Murder is murder. Isn’t that enough? Or conversely, why not call all terrorizing violence terrorism? Why not expand the use of the term to address the imbalance in how attacks by white males are discussed, compared to attacks by Muslims? Why not shun the term altogether?

“Terrorism” is best understood as a term that helps us understand why violence happens, rather than as a pejorative or an amplifier. It’s useful to distinguish between attacks that are related to intentionally violent social movements, and those that emanate from a perpetrator’s personal circumstances. There isn’t a completely clear consensus about the extent to which extremist beliefs routinely produce violent outcomes, but there is no question that extremism shapes the kind of violence that adherents commit. This produces actionable insights for those who are responsible for protecting the public.

Importantly, terrorism is not better or worse than other crimes. Terrorism is not more repugnant than serial rape, and it is not more deadly than ordinary violence.  Some critics of the term often focus, justifiably, on the disparate responses to incidents—from policymakers and media outlets—based on the identity of the victims or perpetrators. That dynamic was on display in the aftermath of the Toronto attack, as some rejected the specter of terrorism because Minassian’s ideology is directed against women, and society often sees violence against women differently—dismissing its significance. For others, the unfamiliar and juvenile beliefs of the incel movement speak more to sexual dysfunction than extremism.

Then there are those who hold violence committed by Muslims to be simply more important and more likely to be prioritized over other kinds of public violence and swiftly presumed to be terrorism—a corrosive assumption that undermines efforts to combat violence and extremism.  

But these problems are not solved by reflexively categorizing all public violence as terrorism, nor by demanding that the term be applied to the actions of a particular identity group when it does not fit the criteria. We can’t solve the biased application of the term “terrorism” by insisting on an equal and opposite bias.

An objective definition of terrorism is both possible and useful—and needs to be applied in a fair, consistent, and color-blind way. That’s the path to placing violent extremism in context and appropriately prioritizing our response.

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