Stimson: The Threat from Within: An Overview of the Domestic Violent Extremist Threat Facing US Nuclear Security Practitioners

“Nuclear security in the U.S. has historically understood threat as ‘other’ – leaving practitioners, facilities, and physical protection systems vulnerable to threats from within: a glaring vulnerability that was made public in the wake of the 2021 Capitol Breach. Urgent change to the nuclear security norms and understanding of threat to include not only foreign agents, but also domestic violent extremist groups and homegrown violent ideologies, is needed to strengthen the resiliency and effectiveness of the national nuclear security regime.

“We are enormously grateful to the U.S. National Nuclear Security Administration, Office of International Nuclear Security’s Nuclear Security Women initiative for the financial support of this project.

Executive Summary

The events of the 21st century have required a reimagining of how nuclear security practitioners perceive threats in the United States. With the rise of terrorism concerns over the last two decades came the increase in the security risk posed by non-state actors to nuclear facilities. Insider threats and non-state actors are the most persistent concerns facing nuclear security practitioners – but the notion of who or what constitutes a threat is so deeply rooted in antiquated understandings of an adversary, that the U.S. nuclear security regime as a whole has struggled to address the risks posed by domestic violent extremists.

The emboldening of non-state actors through the proliferation of accelerationist ideologies among domestic violent extremist (DVE) groups pose a threat, not only to national security, but to the nuclear facilities that make up part of the nation’s critical infrastructure. Compounding these risks are intersections of insider threats and accelerationism that demonstrate the shortcomings in the protective frameworks designed by the traditional national and nuclear security decision-makers in the United States. Traditional assumptions informing security priorities are no longer sufficient to address emerging threats and evolving operational environments, because they fail to adapt to new actors and shifting environments…”