A Situational Model of Displacement and Diffusion Following the Introduction of Airport Metal Detectors

Abstract

Much of the discourse surrounding counterterrorism centers on the inevitability of displacement, or the substitution of another form of terrorist attack in place of the one that has been thwarted. Yet a longstanding tradition of research in situational crime prevention finds that displacement is far from inevitable, and often depends crucially on the specific features of the incidents in question. In fact, crime prevention efforts are often followed by a ''diffusion of benefits'' (i.e., crime reductions) to incidents, groups, or locations that were not the intended target of the intervention. The current study examines various forms of displacement and diffusion in response to airport metal detectors among terrorist groups that had been involved in the perpetration of aviation attacks prior to their implementation. Using data from the Global Terrorism Database, the findings from interrupted time series models suggest a complex set of displacement and diffusion effects with respect to alternative attack modes, target types, and weapon usage.

Examining the state repression‐terrorism nexus: Dynamic relationships among repressive counterterrorism actions, terrorist targets, and deadly terrorist violence in Israel

“…When faced with counterterrorism measures, prior research suggests that terrorists are induced to alter their targeting strategy. For example, a shift from protected official targets (e.g., government agents) to less defended civilian targets after the deployment of target‐hardening measures (Brandt & Sandler, 2010; Hsu & Apel, 2015; Santifort, Sandler, & Brandt, 2012). Particularly worrisome is the potential for increased bloodshed following government counterterrorism policies.…”

What drives terrorist innovation? Lessons from Black September and Munich 1972

“…In this regard, several researchers have also noted the value of using a rational choice perspective in trying to understand and respond to terrorist planning and decision-making, and studies have already identified the rational basis behind terrorist decision-making and how these can identify possible points of intervention to prevent or disrupt effective operations (e.g. Taylor, 1988;Jacobs, 1998;Silke, 2003;Clarke and Newman, 2006;Newman and Hsu, 2012;Hsu and Apel, 2015).…”

Applying situational crime prevention to terrorism against airports and aircrafts.

“…While the literature did find that overall hijackings were deterred because of historical situational reforms (Syzliowicz, 2004;Dugan, LaFree, & Piquero, 2005;Clarke & Newman, 2006;Fahey et al, 2011, Hsu & Apel, 2015, Dugan, LaFree, and Piquero (2005) found that terrorists were not as deterred from attempting an attack as offenders who hijack planes for different reasons. This suggests that different situational techniques may need to be utilized to prevent terrorist attacks.…”

“…Many of the early situational techniques stem from the reforms implemented in the 1970's (Syzliowicz, 2004;Dugan, LaFree, & Piquero, 2005;Clarke & Newman, 2006;Fahey et al, 2011;Hsu & Apel, 2015). These reforms laid the foundations for future situational prevention techniques in airports.…”

“…Hsu and Apel (2015), using the Global Terrorism Database (GTD), found while metal detectors are effective, that both displacement and diffusion can result depending on the types of attack, weapon, or the target being used by the terrorists. A more recent innovation, Advanced Imaging Technology (AIT), has been introduced to airports and has been found to be effective in reducing the risk of an Improvised Explosive Device (IED) from being smuggled on board a plane or further into the airport beyond the security checkpoint (Stewart & Mueller, 2011).…”