One person was murdered in a likely terrorist attack in Charlottesville, Virginia this Saturday when a suspected white nationalist named Alex Fields Jr. drove his car into a group of protesters. Prominent people on both sides of the political spectrum have condemned the politically motivated violence. However, some commentators have pointed out that left wing terrorists and rioters have also committed violence in recent years, though they have not provided any data with which to compare the relative scale of the violence. This blog fills that void by describing terrorist murders and injuries by the political ideology of the perpetrators. Also, though the chance of being murdered or injured in a terrorist attack is minor, there is wide variation in the ideology of terrorists.



Data and Methodology



This post examines 25 years of terrorism on U.S. soil from 1992 through August 12, 2017. Fatalities and injuries in terrorist attacks are the most important measures of the cost of terrorism. The information sources are the Global Terrorism Database at the University of Maryland and the RAND Corporation. Other organizations seem to count many religiously or racially motivated crimes as terrorist offenses, an overcounting that I attempted to avoid. I estimate the number of murders committed by terrorists in 2017 from online sources although they may be incomplete. As much as possible, I excluded terrorists who died or were injured in their attacks as they are not victims.



I grouped the ideology of the attackers into four broad groups: Islamists, Nationalists and Right Wingers, Left Wingers, and Unknown/Other. Global Terrorism Database descriptions of the attackers and news stories were my guide in organizing the groups by ideology. Islamists and unknown/other straightforward. Left Wing terrorists include Communists, Socialists, animal rights activists, anti-white racists, LGBT extremists, attackers inspired by Black Lives Matter, and ethnic or national separatists who also embrace Socialism. Nationalist and Right Wing terrorists include white nationalists, Neo-Confederates, non-socialist secessionists, nationalists, anti-Communists, fascists, anti-Muslim attackers, anti-immigration extremists, Sovereign Citizens, bombers who targeted the IRS, militia movements, and abortion clinic bombers. Some of the marginal attacks are open to reinterpretation but the ideology of the attackers by death and injury are straightforward in virtually all cases.

Findings



Terrorists have murdered 3,342 people on U.S. soil from 1992 through August 12, 2017 (Figure 1). Islamists committed 92 percent of all those murders and are, far and away, the deadliest group of terrorists by ideology. The 9/11 attacks accounted for 2,983 of the 3,085 Islamist-inspired terrorist deaths—an overwhelming 97 percent. The chance of being murdered in a terrorist attack committed by an Islamist during this period was about 1 in 2.5 million per year (Table 1).



Nationalist and Right Wing terrorists are the second deadliest group of terrorists by ideology and account for 219 murders and 6.6 percent of all terrorist deaths. The chance of being murdered in a Nationalist or Right Wing terrorist attack was 1 in 33 million per year. The 1995 Oklahoma City bombing, the second deadliest terrorist attack in U.S. history after 9/11, killed 168 people and accounted for 77 percent of the murders committed by Nationalist and Right Wing terrorists. Left Wing terrorists killed only 23 people in terrorist attacks during this time but 13 since the beginning of 2016. Nationalist and Right Wing terrorists have only killed 5 since then, including Charlottesville. Meanwhile, the annual chance of being murdered by a Left Wing terrorist was about 1 in 330 million per year. Regardless of the recent upswing in deaths from Left Wing terrorism since 2016, Nationalist and Right Wing terrorists have killed about 10 times as many people since 1992. Terrorists with unknown or other motivations were the least deadly.



Figure 1



Murders in Terrorist Attacks by the Ideology of the Attacker, 1992-2017.



Sources: Global Terrorism Database at the University of Maryland, RAND Corporation, ESRI, and author’s calculations.



Table 1



Annual Chance of Dying in a Terrorist Attack by Ideology of Perpetrator, 1992-2017





Terrorist Ideology

Terrorism Deaths per Ideology

Annual Chance of Being Murdered Islamist

3,085

1 in 2,462,626 Nationalist and Right Wing

219

1 in 34,685,286 Left Wing

23

1 in 330,264,250 Unknown/Other

15

1 in 506,405,183 Total

3,342

1 in 2,272,914

Sources: Global Terrorism Database at the University of Maryland, RAND Corporation, ESRI, United States Census, and author’s calculations.



The distribution of injuries committed by terrorists is similarly ideologically skewed (Figure 2). Attacks committed by Islamists are responsible for almost 94 percent of the 17,471 injuries during the entire period. Nationalist and Right Wing terrorists are responsible for 998 injuries, or 5.7 percent of the total. Left Wing terrorists are responsible for 46 injuries, or 0.26 percent of the total. Nationalist and Right Wing terrorists injured about 22 times as many people in terrorist attacks as Left Wingers did during this time.



Injuries is a less clear category of damage that can range from a few scratches to amputations or brain damage. The annual chance of being injured in a terrorist attack does not reveal as much as your annual chance of being injured but I included it anyway (Table 2).



Figure 2



Injuries in Terrorist Attacks by the Ideology of the Attacker, 1992-2017.



Sources: Global Terrorism Database at the University of Maryland, RAND Corporation, ESRI, and author’s calculations.



Table 2



Annual Chance of Being Injured in a Terrorist Attack by Ideology of Perpetrator, 1992-2017





Injuries

Terrorism Injuries per Ideology

Annual Chance of Being Injured Islamist

16,366

1 in 464,138 Nationalist and Right Wing

998

1 in 7,611,300 Left Wing

46

1 in 165,132,125 Unknown/Other

61

1 in 124,525,865 Total

17,471

1 in 434,782

Sources: Global Terrorism Database at the University of Maryland, RAND Corporation, ESRI, United States Census, and author’s calculations.



The risk of being killed or injured in a terrorist attack on U.S. soil is small. However, a comparison to other intentional harms can put the risk in perspective. The chance of being murdered in a non-terrorist homicide from 1992 through 2017 was about 1 in 17,000 a year, which is about 133 times as great as being killed by terrorism during that time.



Islamism is an ideology created overseas, while much of the ideology that inspires Nationalist, Right Wing, and Left Wing terrorism is home grown or it has been here for so long that it might as well be.



Conclusion



Islamist terrorists are the deadliest since 1992. They killed about 14 times as many people as Nationalist and Right Wing terrorists who, in turn, killed about 10 times as many people as Left Wing terrorists did. The deadliness of terrorists by ideology has changed over time and will continue to do so. Charlottesville was a tragedy and the person responsible should be tried and, if convicted, punished to the fullest extent possible under the law. However, it is important to realize that the actual scale and scope of the recent terrorist threat differs significantly by ideology even though the annual chance of being murdered in such an attack is still small.







