How big are risks from non-state actors? Base rates for terrorist attacks

Abstract

This article explores the potential risks posed by non-state actors wielding powerful new technologies. It examines the likelihood of such actors causing widespread harm by considering the number of actors capable and willing to commit acts of violence. The author focuses on the historical base rates of terrorist attacks and provides data on the number of attacks per million group members across various groups, including Northern Irish nationalists, Northern Irish unionists, US Muslims, UK Muslims, the US radical right, US pro-lifers, the UK right, the US radical left, the UK left, US environmentalists, UK environmentalists, vegans, and the world population at large. The article cautions against interpreting these numbers as direct indications of comparative rates of attacks due to inconsistencies in group definitions and data sources. Nevertheless, the data suggests that terrorist attacks are relatively rare even among groups where political or religious violence is sometimes justified, and that most attacks are not motivated by omnicidal intent. However, given the world’s large population, the presented rates of terrorist attacks highlight the potential risks posed by non-state actors, especially with the potential for widespread access to dangerous emerging technologies. – AI-generated abstract.