It's really interesting how people use old data and stick with it. The most apparent are the right's "insistence" that little kid immunizations "cause" things like autism. That study is from almost 30 years ago, and they're finding that genetics may have a role to play. In 2025 (Jan-Jul), left wing terrorist acts account for 42% of the attacks in the US.
From the left, we have the "Steele Dossier" and that the right is more violent than the left.
Historically, that is correct. And yet, here we are. 2025 marks the first time in more than 30 years that left-wing terrorist attacks outnumber those from the violent far right. In recent years, the United States has seen an increase in the number of left-wing terrorism attacks and plots, although such violence has risen from very low levels and remains much lower than historical levels of violence carried out by right-wing and jihadist attackers.
The difference now is the change in there are several characteristics and conditions that limit the scale and sophistication of attacks. The overall low lethality rates in left-wing attacks are probably attributable to several factors, including target selection, target scope, tactical methods employed, low levels of perpetrator skill, and counterterrorism measures. Where Jihadists and other "old school" terrorists (such as the IRA and it's factions, Bader Meinhof, RAF, FARC, etc), generally use a site selected model, which produce mass casualties (the bombing of the Frankfurt Officer's club, San Bernardino, 9/11, etc).
Despite its decline this year, right-wing terrorism could easily return to previous high levels. It is important to resource counterterrorism efforts against both right- and left-wing terrorism. Most of the level III supporters (those that do the act) are woven into everyday society. That's a problem. The other thing is our First Amendment. The only way to slow this down is to work with communities to gain their support against extremists. Leaders across the political spectrum must condemn violent extremism of all kinds, denying it legitimacy and reducing its appeal.
A full methodology and codebook for the dataset is available at CSIS.org.