Pedestrian suicide attacks: managing the threat

In a recent interview, the commissioner of London's Metropolitan Police, Sir John Stevens, suggested that it was only a matter of time before a suicide bomber strikes in London. Despite the enormity of the prediction, the interview only made the inside pages of London's evening newspaper and initiated little interest amongst an increasingly sceptical public.

This scepticism is borne of the premises that the terrorism of 11 September 2001 may have been an isolated incident and that attacks outside the West can be avoided by not travelling to high-risk locales. People have also grown weary of the 'threat', due to the lack of public engagement by government; the assumption that intelligence or other agencies will pre-empt the threat; the lack of disclosure concerning previous alerts (such as the discovery of ricin and the closure of Heathrow Airport); and distrust of the government (and by extension officialdom), in the aftermath of the recent war in Iraq.

Suicide attack has long been used as a weapon of terror but is arguably more effective than ever when used against modern societies. These are characterised by areas of high population concentration (especially at places of work), the development of entertainment and transport, an expectation of longevity and a culture of self-indulgence at the expense of individual sacrifice for the greater good of the community. Additionally, we have become a risk averse society distancing ourselves from and simultaneously fearing death, with a consequent erosion in religious or ideological belief.

Suicide attacks may be defined as 'an act of extreme violence against a target that anticipates the death of the attacker'. Other forms of attack may be thought of - and indeed described as - suicidal insofar as the probability of surviving the attack is low. The single soldier rushing the machine gun position is an example of this, but such attacks are not mounted with the specific intention of the attacker dying. Nor are proxy bombers suicide attackers, although they may die during the attack.

Proxy bombers are motivated by a high level of coercion - usually the family being held hostage and threatened with death - and an expectation of escaping prior to detonation.

Suicide attacks, usually but not necessarily, employ high explosive. Pedestrian suicide attackers (PSAs) have used firearms or blades in the certain knowledge that they will be confronted with lethal force. The vehicle-borne suicide attacker may use the kinetic energy of the vehicle as a weapon in its own right. The same is true of airborne suicide attackers and maritime suicide attackers. In addition, the possibility of suicide attackers of any category carrying chemical, biological or radiological payloads cannot be discounted.

While the death of a biological or radiological suicide attacker may occur some time after the release has taken place, its acceptance as an outcome would nevertheless qualify such an individual as a suicide attacker. However, the most probable current suicide threat in the UK and elsewhere in the West is the PSA utilising high explosive: the PSA(E).

Although it is correct to argue that to defeat terrorism it is necessary to address the causes of terrorism, the immediate response must be the management of the threat. The probability of any individual or location being the victim of a PSA is low, yet the impact of such an attack would be high (indeed potentially catastrophic), resulting in a significant negative impact on the population's psychological and economic wellbeing.

The police in the UK has developed a response based on the modification of lessons learned from colleagues in Israel and Sri Lanka, but a lack of engagement of the wider community is likely to exacerbate the consequences of an attack. The argument against wider engagement is based on an assumption that the public will panic or compromise police counter-PSA operations. Such a case, however, seems fundamentally flawed.

There is little historical evidence to support the contention that the public at large is less able to confront unpleasant realities than members of law enforcement and government organisations who are, after all, drawn from that very same public. It is true that some individuals are more susceptible to increased anxiety, and that exposure and understanding provides professionals with a degree of inoculation from the impact of their involvement with the unpleasant aspects of their work. It is also true that knowledge dispels fear, that an informed society is a resilient society and that practiced incident response reduces the impact of an incident.

While the possibility of compromising a police counter-PSA operation could have a serious impact, it is reasonable to assume that if a PSA has successfully reached his or her target location, the police are either unaware of the pending attack or their operation has been unsuccessful. The choice then lies between taking no action or implementing a procedure that may either prevent an attack or mitigate its effect.

The PSA(E) is likely to use high explosive in quantities similar to that which might be found in a parcel bomb; therefore in destructive potential it is 'just another bomb', the level of threat regularly and successfully confronted during the 30-year Irish republican terrorist campaign. The greater psychological impact of the PSA is borne of the general abhorrence of the act of suicide, combined with the belief that the PSA hates the target population enough to forfeit his or her own life and, in the case of Muslim PSAs, will be rewarded for doing so.

An effective bomb requires a payload (high explosive in the case of the PSA(E)) and usually an effect enhancer such as ball bearings, weaponisation comprising a carrier (container) and initiation unit and a delivery system to provide both mobility and guidance. The PSA might reasonably be considered the 'poor man's smart bomb'. It delivers an effect disproportionate to the size and complexity of the device because it is programmable; able to close with its target rather than adopt a standoff position; has both a physical and a psychological impact; and tends to alienate the PSA's community from the target population and the wider community.

The extensive target array available to the PSA includes sites of iconic/symbolic significance; government, military and representative buildings; critical national infrastructure; economic targets; transport; and centres of population concentration. Regardless of the selected target, the attack will require planning, reconnaissance, preparation and execution, each phase offering an opportunity for effect mitigation by the security forces, with maximum mitigation being achieved by disruption during the planning phase.

The suicide attack involves a number of individuals and groups: the attacker, who may be a committed terrorist or the victim of manipulation; the controller who directs the attack process; the donor population from where the attacker is drawn; the target population; and the counterattack response force.

The desired response to suicide attacks entails pre-emption, which may involve resource denial; the isolation of potential attackers from their supporting population; and causal neutralisation.

The latter can be accomplished by making concessions (and therefore undermining the motivation to volunteer) or by the elimination of the command-and-control component through assassination or arrest. Assassination as a technique poses some profound challenges: as extra-judicial killing, it may isolate the practicing country from its international and internal supporters; there is the probability of significant collateral damage to innocent parties; it may increase the number of terrorist volunteers coming forward; and it results in the suspension of the human rights from a sector of the population.

Other responses available to the security apparatus are interdiction of the attacker en route to the target site or exclusion from the target site. Target site exclusion may result in the selection of an alternative target or a detonation external to rather than inside the chosen target, thereby reducing the number of casualties.

Interdiction, the preserve of the specialist team, is dependent on the identification of a suicide attacker, containment by isolation from potential targets and neutralisation by capture or killing. However, others can contribute to target site exclusion by the application of best security practice at access points. It is worth reminding ourselves that the PSA is a valuable terrorist resource, not to be squandered on attacks that have a low probability of success.

As unpalatable as it may be, the successful identification of the potential PSA dictates profiling. Four predominant groups currently have a credible PSA capability:

· the Black Tigers, the suicide cadre of the Tamil Tigers, who are presently stood down. Even when active, the Black Tigers are not considered a threat beyond the Sri Lankan government, its agencies and its national and regional supporters;

· Chechens who target Russians and Russia's Chechen allies;

· Palestinian groups who target Israelis; and

· supporters of Al-Qaeda.

It is the latter, disparate, group that currently poses the greatest potential threat to the West and indeed the world, as illustrated by the attacks in Casablanca and Bali. A threat profile is rarely absolute but is based on probability, and is equally rarely representative of the position adopted by the vast majority of the ethnic group or religion from which the threat individuals are drawn.

Currently the most likely profile of a PSA is a 15-25 year old male of Middle Eastern ethnic origin or from the Indian subcontinent. Australia is an exception, where the ethnic origin is more likely to be southeast Asian.

Indicators of an imminent attack include heightened anxiety; sweating; glazed eyes; mumbling; clenched fist(s); the wearing of clothing inappropriate to the weather; unnatural bulk; visible wires; or toggles. Naturally there may be legitimate explanations for all of these. If no procedural or structural preparation has been undertaken, however, identification of a PSA will do little to mitigate an attack.

Possible actions to mitigate the PSA threat include:

· Introducing/reinstating protective measures against improvised explosive devices;

· Briefing key personnel on the PSA(E) threat;

· Preparing contingency plans in consultation with the police service;

· Auditing access control and perimeter security measures;

·Identifying 'gatekeepers' and training them to evacuate other staff or customers in the event of an attack;

· Aiming to make the location an unattractive target by demonstrating a high level of vigilance;

· Developing mutual co-operation schemes with neighbouring premises; and

·Undertaking regular in-house briefings and exercises.

Garth Whitty is head of RUSI's Homeland Security and Resilience Programme