Belgian authorities closed down the Brussels-North train station Dec. 27 in response to a telephoned bomb threat while authorities searched the station both visually and with explosive-detecting dogs. This marked the second time in two days the station was closed following an anonymous bomb threat made during the peak evening rush hour. The station was reopened to train, bus and pedestrian traffic after searches turned up nothing, demonstrating that the calls were merely the latest in a long string of hoax bomb threats directed against the station.
When authorities respond this way to an anonymous bomb threat, they cause significant disruptions and give those seeking to propagate terror a cheap, easy victory. Even worse than the fear they generate, such reactions to bomb threats can also provide terrorists with a soft target: Evacuating people from a place of relative security out into the open makes them more vulnerable to attacks with a variety of weapons, including bombs, guns, knives and vehicles.
As its name suggests, terrorism is not just about killing people, but also about creating a pervasive sense of terror and fear. By design, terrorist attacks are intended to leverage violence to create a psychological impact far outweighing the physical damage from the attack, accumulating a toll of vicarious victims far surpassing the physical casualty count. A target population that panics in the face of a terrorist attack therefore enables the perpetrators to obtain a maximum return on their actual effort. Terrorist groups and their sympathizers can also use tools like bomb threats to spread hysteria; these efforts are often most successful in the wake of an actual attack such as the March 2016 attack against Brussels' Zaventem airport.
Beyond the terror and fear bomb threats can create, they can also lead to considerable disruptions and financial costs. When airliners are forced to make emergency landings; airports, bus terminals or subway stations closed; or schools and shopping centers emptied of shoppers, significant disturbances to commerce and people's lives ensue. Hollow threats also consume considerable police resources when explosive ordnance detection teams and other law enforcement resources need to be dispatched, sometimes resulting in significant public costs. Because of these various factors, terrorists and pranksters can resort to bomb threats as a simple way to create mayhem.
Bomb Warnings vs. Bomb Threats
The difference between bomb warnings and bomb threats is crucial. Historically, terrorist groups such as the Provisional Irish Republican Army (PIRA) and the Basque separatist group ETA established coded phrases with the authorities that were used to provide warning of a bombing in order to prevent civilian casualties. Such warnings were generally telephoned into a police station or media outlet with the intention of providing enough time for civilians to evacuate an area, but not enough time for the bomb squad to deactivate the device before its detonation.
Groups that employed such warnings obviously sought to limit civilian casualties, the exact opposite motive of jihadist terrorists, for whom groups of civilians from Baghdad to Bali to Boston have become the primary target. Such warnings would naturally cut against the jihadist goal of generating maximum civilian casualties. And since jihadists simply don't make warning calls, any bomb threat purportedly from jihadists should be approached with a great deal of skepticism.
Context is incredibly important for understanding how to correctly analyze a bomb threat call.
Obviously, a call related to a group operating like the PIRA or ETA that uses coded signals as bomb warnings should be handled far differently than a call received from a jihadist group that does not use such calls. And calls purportedly from jihadists should be treated differently from calls from some animal rights activists, many of whom do not purposefully seek to kill or injure people when they damage property with bombs. Because of these distinctions, the identity of the group or cause purportedly making the threat is very important.
Beyond the code words used in legitimate bomb warning calls and the nature of the group making the claim, the information contained in warning messages has historically proved to be quite different from that used in hoax threats. Bomb warning calls tend to be very specific, noting the type of bomb involved, its location and the planned time of detonation. On the other hand, hoax bomb threats intended to scare or disrupt tend to be very general, rarely if ever containing specifics. In addition to being vague, hoax bomb calls most often threaten multiple targets, more than most legitimate terrorists are in fact capable of bombing. The rash of bomb threats earlier this year against schools worldwide by a group calling itself "Evacuation Squad," which in some cases threatened 10 or more schools in the same city, falls into this category. It eventually emerged that Evacuation Squad had offered to issue bomb threats to schools in return for a fee payable in bitcoins.
Based on decades of experience resulting in a deep understanding of bomb threats, U.S. government policy has long been to urge employees to carefully note the language used in threatening calls in accordance with guidance contained within widely distributed bomb threat call checklists.
Many government agency phone books have the bomb checklist in a prominent place. Switchboard and emergency call center operators are furnished with copies of the lists and trained how to handle such calls. People receiving threatening calls are encouraged to take careful notes, question the caller, record the call if possible and attempt to get a second person on the line to listen. Because of this procedure, it is very rare for personnel in U.S. government buildings to be evacuated in response to a bomb threat. Most agencies conduct periodic bomb threat drills in which the objective is to quickly and efficiently sweep the building for suspicious items rather than just evacuate the building as during a fire drill, employing the logic that workers are more likely than outsiders to know what is normal in their work areas versus what is suspicious.
The evacuation of part or all of a building is only considered after a suspicious item has been found. This is intended not only to help combat disruptions, but also to prevent an unnecessary evacuation of a building that could take employees from a place of relative security to an outside area where they would be more vulnerable to attack. Employees inside a large office building are far less vulnerable to injury or death from a small device such as a pipe bomb than are employees standing in a parking lot or on the street. By contrast, the recent hoax threats seen in Brussels resulted in immediate evacuations.
An Intelligent Response
On one level it is easy to understand why people make the call to evacuate the purported target of the hoax threat. Many consider this the safest course of action, oftentimes partially based on the thinking that this will prevent them from being blamed if there actually turns out to be an explosive device. An evacuation and high-profile police search of the premises can also provide the public with emotional reassurance that something is being done about the perceived threat.
Even so, automatic evacuation is not the best action when a non-specific bomb threat is received or a threat is made in the name of a group, such as the Islamic State, that does not issue bomb threats before attacks. In cases when the threat does not identify a specific classroom or building, sending people out into the open air can put them in more danger than keeping them in place. Besides, given a non-specific threat, the potential device could be anywhere, including outside the building. Indeed, it is generally easier to place a device outside a building than to get one inside, especially when the target has viable security. By sending people outside, authorities send them from a place of relative safety to one where they are far more vulnerable to attack.
Intentional attacks are not the only danger that can arise in the wake of an evacuation.
In May, the Los Angeles Unified School District closed down all 900 Los Angeles schools after receiving an email claiming that 32 people were preparing to attack Los Angeles schools with explosive devices containing a nerve agent. A 17-year-old student was killed after being struck by a city street service vehicle after the closure, amplifying the criticism received by the Los Angeles School Board for responding to such an obvious hoax threat. Unlike in Los Angeles, New York schools — which received an identical threat at almost the same time as Los Angeles — chose to stay open.
Stratfor has previously discussed how "hunter" terrorists can use panic and herd mentality to induce people to stampede into a designated kill zone. In a bomb threat situation, security managers who decide to evacuate a facility can actually aid attackers by forcing people to congregate in an assembly area that terrorist planners have identified and planned to make into a kill box. This is especially true in situations where people evacuated from a building are required to report to designated assembly areas for accountability purposes. We would encourage people who are forced to evacuate from a facility to heighten their level of situational awareness and be aware of the possibility of an attack against an assembly area and be prepared to take action to avoid potential threats. We would also urge security directors to carefully examine their bomb threat policies and procedures and consider measures such as resisting evacuation or instituting remote check-in procedures that can help prevent exposing their employees or customers to danger in a vulnerable assembly area.