Terrorism and the IED - Part I

According to Dobson and Payne, in 1985 "the British Army estimated the PIRA [Provisional IRA] relied on only four or five master explosive experts."1 What is an IED? What factors influence IED design and deployment? Who is involved with the development, production and subsequent deployment of an IED? What is understood by the term 'master bombmaker/top bombmaker'? Repeatedly the media refer to bomb attacks and the individuals responsible for such criminal acts. Such reports, however, are often misleading and erroneous.

The media consistently reminds us that the terrorist threat is never very far away. In Colombia, terrorists carry out attacks on government installations utilising improvised munitions, such as the car bomb and improvised mortar. In the Middle East, the terrorist group Hamas have developed an indigenous improvised rocket system for use against Israeli targets. In Chechnya, extremists have used a variety of improvised devices to attack Russian security forces operating in the region, and in Northern Ireland dissident terror groupings are determined to use IEDs to destroy the fragile political situation.

There are a number of reasons why IED development should be researched in more detail. Primarily it is simply because the problem will not go away. Secondly, if one can understand what drives the bomb design and development process, one may well be able to influence the attack capability of a particular group by applying counter-terrorist measures to certain key areas - for example, the recruitment of technical personnel. Finally, if one can predict what types of devices are likely to be encountered within a certain geographical location and why, countermeasures can also be taken to reduce that threat.

What is an IED?

In official/military circles an IED is defined as: "Those devices placed or fabricated in an improvised manner incorporating destructive, lethal, noxious, pyrotechnic or incendiary chemicals. Designed to kill, destroy, disfigure, distract or harass."2

Such a definition encompasses a vast range of attack options, varying from improvised munitions containing an explosive fill or incendiary mix to poisonous gas. An IED may consist solely of improvised components or a combination of commercially available (including military) and improvised items. For example, a device may consist of home-made explosive and a commercial/ military detonator or a home-made detonator and home-made explosive. Timing and initiation systems are often improvised, while explosive charges are regularly obtained from commercial or military sources unless a considerable amount is required, in which case the explosive is likely to be home-made.

Military explosives and accessories are often obtained by terrorist groups during or after a period of regional conflict, the war in the Balkans being a good example. Irish terrorists attempted, with some success, to procure explosives and other items from this area. Chechen extremists have often fabricated devices that consist of military ordnance - artillery projectiles or mortar rounds, for example, and improvised timing devices adapted from Casio wristwatches. In the 1950s the Cypriot group EOKA often recovered explosives that had been dumped into the sea at the end of the Second World War in order to produce IEDs for use against British security forces. These examples serve to illustrate that IEDs can consist of a wide variety of components depending upon their availability in the region.

In addition to being an indicator of a terror grouping's available resources, the type and make up of the IED deployed by the terrorist is usually a good indicator of that grouping's technical capability, level of support and level of motivation. Post-blast investigators examining Hizbullah IED attack locations in Lebanon against the Israelis have frequently discovered sophisticated components amongst the debris.

Why carry out bomb attacks?

There are a number of reasons why the IED will remain the mainstay of the terrorist arsenal. Bomb attacks are an effective way of highlighting a cause, particularly in view of the power of the modern media. Bomb attacks can have significant economic effects that penetrate the heart of a government; something recognised by the Provisional IRA when it bombed the Baltic Exchange in 1992 and Bishopsgate in 1993. It was suggested at the time that the British economy could not withstand many more attacks of this nature. Tourism alone can be seriously affected by such attacks, for example in Bali and New York.

The political, economic and physical impact of a bombing campaign far outweigh the cost to the terrorist in terms of the time spent fabricating the device and its financial outlay, particularly if the bomb was improvised from 'off-the-shelf' components; therefore the 'cost-benefit' ratio is high.

Why terrorists produce IEDs

One of the core reasons behind IED design and production is necessity. The Israel Defence Force, for example, effectively controls all resources moving into the West Bank and Gaza City. Certain household items that one would expect to find on the shelf in the UK, such as camera flash bulbs, numerous chemicals associated with horticulture and various types of fireworks, are banned. Extreme border controls prevent the large-scale acquisition of commercial explosives/weapon systems, and therefore the terror group Hamas has been forced to improvise weapon systems and explosives such as triacetonetriperoxide (TATP), which is used in detonators and main explosive charges. The process of manufacturing TATP is extremely dangerous, and a number of houses have 'mysteriously' disappeared in the middle of the night due to unexpected chemical reactions while mixing the substance. Such 'own goals' may indicate a level of desperation on the part of Hamas.

An IED is generally cheaper and easier to manufacture or obtain than a commercially available item that may have a similar purpose, although it is not necessarily as effective. Most IEDs are fabricated from whatever materials are locally available. Although this is often done through necessity, this has the added advantage of reducing the involvement of third parties or individuals who might be acting as informants for the security forces. One of the primary concerns of any terror grouping is security, and it is vital that the 'circle of knowledge' of any operation or method is kept to a minimum. Many commercially available items such as weapons and explosives have batch and serial numbers, which can be traced back easily to a particular person, location and time. In addition, in recent years explosive detection methods have evolved and taggants (readily detectable substances) are now included in explosives at the manufacturing stage. Most modern explosive particle detection equipment is calibrated to detect commercial explosives such as trinitrotoluene (TNT), nitroglycerine based explosives and plastic explosives consisting of RDX (Royal Demolition eXplosive) and PETN (pentaerythritol tetranitrate). Home-made explosives are certainly not produced with taggants or any official batch number, making them harder to detect.

In some cases IEDs may be deliberately used in order to disguise the fact that a state sponsor was behind an attack; the absence of commercial explosives or components may convince any post-blast investigator that the attack was the work of a terrorist grouping with limited resources. Terrorist 'active service' operations may be conducted against a target that has to be engaged in a particular fashion and there may be no commercially available weapon/explosive system to satisfy the operational requirement. Therefore the terrorist will improvise/fabricate a bespoke device purely for that purpose. One example would be the Red Army Faction attack in November 1989 against Alfred Herrhausen in Germany. The terrorists targeted Herrhausen's armoured vehicle using an improvised shaped charge and active infrared initiation system. Other examples would be the use of an under car booby trap, sensory detonation systems and long-term time delay electronic circuits.

Primarily, however, the terrorist will improvise when restrictions are placed upon the acquisition of resources and when he wants to avoid any unnecessary security breaches. Necessity is often described as the 'mother of all invention'. The organisation behind the attacks of 11 September 2001 gives a useful example: "When an Al-Qaeda member left Afghanistan on a mission, he was not expected to take weapons or explosives with him; instead he was taught to be self-sufficient, to manufacture an explosive device from commercial products, and to procure, transport and store munitions near his target."3

John Allison is a counter-terrorism analyst and is currently a PhD student at the University of St Andrews


1. Christopher Dobson and Ronald Payne, War Without End - The Terrorists: An Intelligence Dossier (London, Harrap, 1986).

2. This is the IED definition used by NATO forces.

3. Rohan Gunaratna, Inside Al Qaeda: Global Network of Terror (London, Hurst and Company 2002), p82.


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