Assessing the risk of nuclear terrorism is a challenging task due to the diversity of actors involved, variety of pathways to success, range of defensive measures employed, and the lack of detailed historical record upon which to base analysis. Numerical models developed to date vary wildly in both approach and ultimate assessment: estimates of the likelihood a nuclear terrorist attack differ by up to nine orders of magnitude. This article critiques existing efforts from the standpoint of probability theory, and proposes an alternative perspective on the utility of risk assessment in this area. Nuclear terrorism is argued to be a ‘virtual risk’ for which it is not possible to meaningfully ascribe a quantitative measure, making numerical estimates of the likelihood of nuclear terrorism misleading. Instead, we argue that focus should be placed on utilising models to identify areas of disagreement as targets for further research, with greater emphasis on understanding terrorist decision-making and adaption in response to nuclear security measures.

A nuclear detonation in a US city would have profound psychological, social, and behavioral effects. This article reviews the scientific literature on human responses to radiation incidents and disasters in general, and examines potential behavioral health care provider (BHCP) contributions in the hours and days after a nuclear detonation. In the area directly affected by the blast, the immediate overarching goal of BHCP interventions is the support of lifesaving activities and the prevention of additional casualties from fallout. These interventions include 6 broad categories: promoting appropriate protective actions, discouraging dangerous behaviors, managing patient/survivor flow to facilitate the best use of scarce resources, supporting first responders, assisting with triage, and delivering palliative care when appropriate. At more distant sites, BHCP should work with medical providers to support hospitalized survivors of the detonation. Recommendations are also made on BHCP interventions later in the response phase and during recovery.

(Disaster Med Public Health Preparedness. 2011;5:S54-S64)

Developing a mass-casualty medical response to the detonation of an improvised nuclear device (IND) or large radiological dispersal device (RDD) requires unique advanced planning due to the potential magnitude of the event, lack of warning, and radiation hazards. In order for medical care and resources to be collocated and matched to the requirements, a [US] Federal interagency medical response-planning group has developed a conceptual approach for responding to such nuclear and radiological incidents. The “RTR” system (comprising Radiation-specific TRiage, TReatment, TRansport sites) is designed to support medical care following a nuclear incident. Its purpose is to characterize, organize, and efficiently deploy appropriate materiel and personnel assets as close as physically possible to various categories of victims while preserving the safety of responders. The RTR system is not a medical triage system for individual patients. After an incident is characterized and safe perimeters are established, RTR sites should be determined in real-time that are based on the extent of destruction, environmental factors, residual radiation, available infrastructure, and transportation routes. Such RTR sites are divided into three types depending on their physical/situational relationship to the incident. The RTR1 sites are near the epicenter with residual radiation and include victims with blast injuries and other major traumatic injuries including radiation exposure; RTR2 sites are situated in relationship to the plume with varying amounts of residual radiation present, with most victims being ambulatory; and RTR3 sites are collection and transport sites with minimal or no radiation present or exposure risk and a victim population with a potential variety of injuries or radiation exposures. Medical Care sites are predetermined sites at which definitive medical care is given to those in immediate need of care. They include local/regional hospitals, medical centers, other sites such as nursing homes and outpatient clinics, nationwide expert medical centers (such as cancer or burn centers), and possible alternate care facilities such as Federal Medical Stations. Assembly Centers for displaced or evacuating persons are predetermined and spontaneous sites safely outside of the perimeter of the incident, for use by those who need no immediate medical attention or only minor assistance. Decontamination requirements are important considerations for all RTR, Medical Care, and Assembly Center sites and transport vehicles. The US Department of Health and Human Services is working on a long-term project to generate a database for potential medical care sites and assembly centers so that information is immediately available should an incident occur.

There have been numerous unsuccessful attempts to define terrorism generically in international treaty law since the 1920s, from early conferences on the unification of criminal law to efforts in the League of Nations, the International Law Commission, and the UN General Assembly. While these sources do not carry great weight as evidence of customary law, they illustrate the recurring normative and political disputes surrounding definition and elucidate the basic features of an international prohibition and/or crime of terrorism, as perceived by different international actors. The recurrent attempts at definition indicate that the international community attaches considerable normative importance to it. Drafting of a UN Comprehensive Terrorism Convention continues in the Sixth Committee, and the UN High-Level Panel on Threats, Challenges and Change advocated definition in treaty law in late 2004. Generic definition of terrorism can capture and stigmatize the political motives which distinguish terrorism from ordinary violent crime, or transnational organized crime for financial benefit. Following an historical pattern, agreement on the scope of any exceptions to a definition of terrorism remains the key obstacle, although much of the argument about exceptions is ideological, not substantive.

The prediction of future disasters drives the priorities, urgencies, and perceived adequacies of disaster management, public policy, and government funding. Disasters always arise from some fundamental dysequilibrium between hazards in the environment and the vulnerabilities of human communities. Understanding the major factors that will tend to produce hazards and vulnerabilities in the future plays a key role in disaster risk assessment.

The factors tending to produce hazards in the 21st Century include population growth, environmental degradation, infectious agents (including biological warfare agents), hazardous materials (industrial chemicals, chemical warfare agents, nuclear materials, and hazardous waste), economic imbalance (usually within countries), and cultural tribalism. The factors tending to generate vulnerabilities to hazardous events include population growth, aging populations, poverty, maldistribution of populations to disaster-prone areas, urbanization, marginalization of populations to informal settlements within urban areas, and structural vulnerability.

An increasing global interconnectedness also will bring hazards and vulnerabilities together in unique ways to produce familiar disasters in unfamiliar forms and unfamiliar disasters in forms not yet imagined. Despite concerns about novel disasters, many of the disasters common today also will be common tomorrow.

The risk of any given disaster is modifiable through its manageability. Effective disaster management has the potential to counter many of the factors tending to produce future hazards and vulnerabilities. Hazard mitigation and vulnerability reduction based on a clear understanding of the complex causal chains that comprise disasters will be critical in the complex world of the 21st Century.