Terrorism is one of the serious threats to international peace and security that we face in this decade. No nation can consider itself immune from the dangers it poses, and no society can remain disengaged from the efforts to combat it. The termcounterterrorism refers to the techniques, strategies, and tactics used in the ?ght against terrorism. Counterterrorism efforts involve many segments of so- ety, especially governmental agencies including the police, military, and intelligence agencies (both domestic and international). The goal of counterterrorism efforts is to not only detect and prevent potential future acts but also to assist in the response to events that have already occurred. A terrorist cell usually forms very quietly and then grows in a pattern – sp- ning international borders, oceans, and hemispheres. Surprising to many, an eff- tive “weapon”, just as quiet – mathematics – can serve as a powerful tool to combat terrorism, providing the ability to connect the dots and reveal the organizational pattern of something so sinister. The events of 9/11 instantly changed perceptions of the wordsterrorist andn- work, especially in the United States. The international community was confronted with the need to tackle a threat which was not con?ned to a discreet physical - cation. This is a particular challenge to the standard instruments for projecting the legal authority of states and their power to uphold public safety. As demonstrated by the events of the 9/11 attack, we know that terrorist attacks can happen anywhere.

This document is a preliminary report on the role that mathematical and statistical methods might play in the defense against terrorist attacks. In no way does this replace the efforts of law enforcement agencies or intelligence activities. The hope is that mathematical techniques can make their efforts more efficient. The ideas enumerated here utilize the notion of Probabilistic Risk Analysis, which was developed for the purpose of assessing the safety of nuclear reactors, as well as randomization and game theory. More extensive work in these directions is contemplated for the future. The author is planning workshops to evaluate the ideas presented here and to elicit additional methodologies which may prove useful in this endeavor.

This work represents the latest in mathematical and computational techniques to assist in combating terrorist cells. Achieved by quantifying threats and the effectiveness of counterterrorism operations and strategies, contributors share theories and methodologies to generate and analyze terrorist networks and provide mathematical methods and practical algorithms for destabilizing adversaries. New developments include: A new centrality-like measure to screen networks for potential actors of interest; Detection of topological characteristics of these networks to understand structure; Measures based on efficiency of networks to identify key players; Theories to detect command structures of networks by detecting hidden hierarchies; A knowledge base of the terrorist attacks in / planned in the past, by spidering data. Results of command structure via new algorithms with SNA literature (N-Clique, K-Core, etc.) are compared. The best techniques are combined to assist intelligence agencies / law enforcement.

Terrorist groups throughout the world have been studied primarily through the use of social science methods. However, major advances in IT during the past decade have led to significant new ways of studying terrorist groups, making forecasts, learning models of their behaviour, and shaping policies about their behaviour. Handbook of Computational Approaches to Counterterrorism provides the first in-depth look at how advanced mathematics and modern computing technology is shaping the study of terrorist groups. This book includes contributions from world experts in the field, and presents extensive information on terrorism data sets, new ways of building such data sets in real-time using text analytics, introduces the mathematics and computational approaches to understand terror group behaviour, analyzes terror networks, forecasts terror group behaviour, and shapes policies against terrorist groups. Auxiliary information will be posted on the book’s website. This book targets defence analysts, counter terror analysts, computer scientists, mathematicians, political scientists, psychologists, and researchers from the wide variety of fields engaged in counter-terrorism research. Advanced-level students in computer science, mathematics and social sciences will also find this book useful.

With the realization that many clues and hints preceded the September 11 terrorist attacks, statisticians became an important part of the global war on terror. This book surveys emerging research at the intersection of national security and statistical sciences. In it, a diverse group of talented researchers address such topics as Syndromic Surveillance; Modeling and Simulation; Biometric Authentication; and Game Theory. The book includes general reviews of quantitative approaches to counterterrorism, for decision makers with policy backgrounds, as well as technical treatments of statistical issues that will appeal to quantitative researchers.

This book is nothing less than a complete and comprehensive survey of the state-of-the-art of terrorism informatics. It covers the application of advanced methodologies and information fusion and analysis. It also lays out techniques to acquire, integrate, process, analyze, and manage the diversity of terrorism-related information for international and homeland security-related applications. The book details three major areas of terrorism research: prevention, detection, and established governmental responses to terrorism. It systematically examines the current and ongoing research, including recent case studies and application of terrorism informatics techniques. The coverage then presents the critical and relevant social/technical areas to terrorism research including social, privacy, data confidentiality, and legal challenges.

This book follows the methodologies of complex adaptive systems research in their application to addressing the problems of terrorism, specifically terrorist networks, their structure and various methods of mapping and interdicting them as well as exploring the complex landscape of network-centric and irregular warfare. A variety of new models and approaches are presented here, including Dynamic Network Analysis, DIME/PMESII models, percolation models and emergent models of insurgency. In addition, the analysis is informed by practical experience, with analytical and policy guidance from authors who have served within the U.S. Department of Defense, the British Ministry of Defence as well as those who have served in a civilian capacity as advisors on terrorism and counter-terrorism.