A year ago, we published Deterrence by Denial, a highly acclaimed collection of essays that, according to Professor Jeffrey W. Knopf, “provides a long overdue exploration of deterrence by denial, which has always received less attention than deterrence by punishment.” The book, which assembles what Sir Lawrence Freedman calls a “stellar collection of contributors,” is and will continue to be a critical resource for students and scholars alike. To celebrate the anniversary of its publication, we’re publishing excerpts from each chapter. This is an excerpt from Chapter 4: “Dissuasion by Denial in Counterterrorism” by Professor John Sawyer.

Although the concept of counterterrorism has grown over the years to include a wide range of tactics and approaches, there are two fundamental goals to be considered in developing a counterterrorism strategy: 1) mitigating the effects of terrorist attacks when they occur, and 2) preventing the adversary from carrying them out in the first place. Given the variety of means to accomplish these goals, the specific attributes of the terrorist threat, and the need to weigh these counterterrorism goals against other societal imperatives, there is no one-size-fits-all counterterrorism strategy. It is therefore essential to have a flexible but coherent framework to evaluate the rationale and likely effects of a counterterrorism policy within a given context. The framework provided in this chapter builds on a model of terrorism/counterterrorism as a dynamic interaction between one or more attackers (or challengers) and one or more defenders, each with a variety of actions available to them to pursue divergent interests.

If one assumes that both defender and attacker have some basic rationality, their interactions are defined by some kind of cost-benefit analysis given the perception of the other’s likely behavior. While both the defender and attacker have their own decision calculus for defining optimal strategies, this chapter will focus primarily on the adversary’s decision-making—and opportunities for its manipulation. An adversary’s decision calculus is characterized by an estimation (with some degree of uncertainty) of the costs and benefits of both action and inaction. The adversary’s costs include the consumption of resources by the action itself or from natural attrition, the risk of larger organizational losses, and negative perceptions within its constituent base. The adversary’s benefits include acquiring leverage over the defender, enhancing the organization’s capabilities, and positive perceptions within the pool of potential recruits or supporters (including current members). However, it is critical to recognize that given resource constraints, an adversary cannot choose a behavior whose costs exceed available resources no matter how beneficial the behavior would be.

As such, there are three basic, potentially overlapping approaches to achieving these counterterrorism goals, each of which targets a different part of the adversary-defender strategic interaction: defense focuses on the defender’s vulnerabilities and costs; offense focuses on the adversary’s capabilities; and influence focuses on the adversary’s perceptions of likely costs and benefits.”

John Sawyer

Deterrence by Denial: Theory and Practice edited by Alex Wilner and Andreas Wegner is available in hardcover. It is also available in different ebook formats, which start at $19.99 to purchase and $9.99 to rent. Professors who wish to use this book along with others in the Rapid Communications in Conflict and Security Series for their classes should use the Cambria Book Cloud, which allows for the bundling of ebooks at only $9.99 per title for each student.