CBRN Attack Perpetrators: An Empirical Study


  • Author’s Note: Kate Ivanova is an Assistant Professor; Todd Sandler is the Vibhooti Shukla Professor of Economics and Political Economy. The authors thank Gary Ackerman of the Monterey Institute of International Studies for providing the WMD data. We also thank the School of International Relations, University of Southern California, for funding data acquisition on rule of law and corruption. We have profited from the comments of three anonymous referees. This research was partially supported by the U.S. Department of Homeland Security (DHS) through the Center for Risk and Economic Analysis of Terrorism Events (CREATE) at the University of Southern California, grant number N00014-05-0630. However, any opinions, findings, and conclusions or recommendations are solely those of the authors and do not necessarily reflect the views of the DHS.


Based on zero-inflated negative binomial regressions applied to the Monterey weapons of mass destruction data, this article assesses the future risks from chemical, biological, radiological, and nuclear (CBRN) terrorism. Once the threshold for CBRN attacks is surpassed, further attacks arise: the expected number of CBRN incidents is over one and a half times higher than past events. Religious cults and groups with a transnational orientation pose the largest CBRN threat to society. Other things constant, nationalists/separatists and religious fundamentalists are not more apt to engage in CBRN terrorism than compared to “other groups.” Democratic and corrupt regimes are the likely venues for CBRN incidents. Based on past incidents, rich countries are especially vulnerable to CBRN terrorism. Thus, recent actions by the U.S. Department of Homeland Security to put more resources into guarding against CBRN attacks appear sound. This study indicates that nonfundamentalist terrorists also present CBRN risks to democracies. From a foreign policy viewpoint, CBRN terrorism is not a problem that rich democratic countries can confront alone, because the terrorists will move to where there is the least vigilance. Our study indicates the likely perpetrators and types of attacks that nations must cooperate to avoid.