The threat posed by weapons of mass destruction (WMD) continues to serve as a key concept for shaping U.S. national security strategy. For many decades, policymakers and experts alike have assumed that malicious actors will seek WMD for their potential to cause mass casualties and destruction. And yet, the historical record of use cases for chemical, biological, radiological, and nuclear weapons (CBRN) over the past three decades is not consistent with their designation as weapons of “mass destruction.” While their potential for mass destruction remains catastrophic, most WMD attacks have involved the use of chemical, biological, or radiological materials for targeting individuals (e.g., assassinations) or to produce targeted casualties in specific populations (e.g., tactical use of chemical agents). Additionally, the world has seen significant political, technological, and structural changes since the concept of WMD focused specifically on CBRN in U.S. national security strategy.
The current technological landscape is generating many new scenarios capable of causing mass effects, which arise from the complexities of the digital and modern world. New technologies such as drone swarms and cyber weapons have the potential to rise to the level of a notional WMD. The convergence of multiple technologies in unexpected ways could generate high levels of destruction and casualties.
Nefarious actors seeking to cause mass effects are likely to consider a broader range of options for achieving their goals rather than seeking WMD in isolation. Over the past three decades, most actors appear to be using WMD for deterrence and to capitalize on their disproportionate psychological effects and their significant advantage of mass publicity. As they are currently defined, the emphasis on WMD in U.S. national security not only misses important gaps in the mass effect threat spectrum, it fails to examine the increasing use of CBRN at the lower end of that spectrum.
What makes a weapon of mass destruction a WMD? What are the criteria for designating a potential weapon as such? Despite the relative importance of WMD to U.S. national security policy, there are no satisfying answers to these questions. The specific characteristics of a WMD have not been adequately debated among policymakers in past decades. Meanwhile the designation of a weapon as WMD conveys major policy implications. As discussed in the first briefer in this series, the recent debate on whether or not fentanyls constitute WMD demonstrates just how outdated the boundaries for consideration are within the U.S. government.
U.S. policymakers need a better way to consider and prioritize emerging threats with mass effects potential in the 21st century.
Read the full briefer here.
 See Natasha E. Bajema, Beyond Weapons of Mass Destruction: Time for a New Paradigm? Washington D.C.: The Council on Strategic Risks, 2021; Natasha E. Bajema, Definitions Matter: The Role of WMD in Shaping U.S. National Security Strategy, Washington D.C.: The Council on Strategic Risks, 2021.
 William C. Yengst, “Next Generation Weapons of Mass Effect,” in Lewis A. Dunn et al, Next Generation Weapons of Mass Destruction and Weapons of Mass Effects Terrorism, January 2008, Advanced Systems and Concepts Office, Defense Threat Reduction Agency, Report Number ASCO 2008 001.