IEDs: the insurgents’ deadliest weapon

What exactly is an IED?

The term "Improvised Explosive Device" refers, loosely speaking, to any jerry-rigged bomb dating back to the Gunpowder Plot. But since the invasion of Iraq in 2003, it has come to describe the lethal variety of roadside, truck-mounted and suicide bombs used by insurgents against coalition forces and Iraqi and Afghan civilians. The devices, hidden in potholes, amidst rubbish and even inside animals, have accounted for around 70 per cent of America's 4,207 combat deaths in Iraq and wounded more than 38,000 US soldiers. IEDs have also accounted for 100 of the 235 British soldiers killed in hostile action in Iraq and Afghanistan.

But haven't IEDs been used in other conflicts?

Certainly. In WWI, T.E. Lawrence used railway and roadside bombs to disrupt Turkish supply routes and create, as he put it, "an uncertain terror for the enemy". Belarussian guerrillas used IEDs in WWII to derail German trains. In Vietnam, IEDs caused a third of all US casualties; in Northern Ireland the Provos made wide use of IEDs, from simple petrol bombs to more sophisticated remote-controlled devices, such as the 1984 Brighton hotel bomb. What marks them out in Afghanistan and Iraq is that they have become the "signature" weapon of the conflict.

Why is the IED regarded as the "signature" weapon?

Because of the extent and effectiveness of its use. In Ulster, British troops encountered 7,000 IEDs in 30 years of conflict. In just four years of conflict in Iraq, from 29 March 2003 - when four US soldiers, searching a taxi at a checkpoint near Najaf, were blown to bits by 100lbs of C-4 explosive in the boot - to mid-2007, there were 81,000 IED attacks. Such attacks have been rarer in southern Iraq, where most UK forces are stationed, but are ever more prevalent in Afghanistan. There were 22 in 2002; between April and June this year, there were more than 200. The Pentagon, which this summer reported more than 100 attacks per day, calls the IED "the single most effective weapon" used against the coalition. "It has levelled the battlefield in favour of insurgent and terrorist groups," says ex-CIA man Robert Baer.

Why have IEDs proved so effective against the coalition?

Partly because they're cheap, simple to build, and, given their limitless variety, hard to spot and defend against. But also because they are so strategically effective. They don't just maim and kill coalition soldiers; they make every civilian a suspect, every car a possible bomb, and drive up hostility against the local populace. The massacres of Iraqi civilians by US marines in Haditha in 2005 and by Blackwater, the security firm, in Baghdad last year both followed IED attacks. Like booby traps in Vietnam, IEDs are a symptom of a broad-based insurgency. "The IED is the enemy's artillery system," says US general Montgomery Meigs. "They didn't come through three-dimensional space in a parabolic trajectory. They came through a social trajectory and a social network in the community."

How are IEDs made?

"All you need is a battered old car, a couple of hundred pounds of homemade explosives and a detonator," says Robert Baer. In Iraq, nearly all the bombs were initially made from the 650,000 tons of explosives left in Saddam's armouries. But they have now evolved to include artillery shells powerful enough to kill soldiers inside 30-ton fighting vehicles, and detonators that can be triggered by such familiar technology as dishwasher timers and cordless phones. And any advance in their technology is quickly spread on the internet.

And are all such bombs "home-grown"?

Probably not. The US military is convinced, for instance, that IEDs first developed by Hezbollah against Israeli soldiers have been imported to Iraq. Iran has also been heavily implicated in the development of the so-called "Explosively Formed Projectile" or EFP, which first appeared in Iraq in 2005 and fires a molten bolt, often of copper, through the armour of the most heavily built vehicles. "Believe me, you don't want to know what that does to the guys inside," a US marine told The Sunday Times.

And how has the coalition tried to deal with IEDs?

Spearheading the US attempt to counter IEDs is the clumsily titled Joint Improvised Explosive Device Defeat Organisation (JIEDDO) which has already spent more than £8bn on force protection measures (Britain's entire military budget is £34bn). Most of that has gone on technological - or "right of boom" - solutions: on heavier armour and sturdier vehicles (by contrast, British soldiers are still heavily reliant on the Snatch Land Rover, which offers no protection against IEDs); on 37,000 radio jammers to disrupt detonators; on more than 6,000 drones and robots; and on ever more bizarre techniques for detecting bombs, including honeybees and hunting dogs. However, since IEDs are constantly undergoing adaptation, the scientific response always tends to be a step behind, so increasingly JIEDDO has been devoting attention to "left of boom" solutions - for example, on anthropologists and data experts working on the social dynamics of insurgent groups and on where the next set of IED attacks is likely to occur.

And is JIEDDO's strategy making any progress?

The US army reports a 50 per cent drop in IED attacks from 2007 to 2008 and an even greater fall in casualties. Some 66 US soldiers died in Iraq in September 2007, mostly from IEDs, against just three in September 2008. More devices are being found before they go off, while body armour and stronger vehicles are also improving so-called "survivability ratios". Critics, however, say it is impossible to distinguish the effects of the anti-IED campaign from the broader success of the US surge in Iraq, and point to the rise of attacks in Afghanistan, where counter-measures have proved ineffective. Prince William's former instructor at Sandhurst, for instance, lost radio contact with the rest of his patrol in Helmand on account of his radio jammer - and was killed by an IED.

Refining the roadside bomb

An especially worrying aspect of the IED phenomenon is the ease with which the technology is spread. Bombers film their attacks, then post the footage on the internet, along with instructions on how to make the devices, so techniques are constantly being shared and refined by hundreds of insurgent groups. For example, in Afghanistan, more and more IEDs are being set off by text message, a trend that will rise as the country develops its mobile phone network. There are more than 5,000 jihadi websites, all mimicking the user-generated content of sites like Facebook. Security experts say there are now up to 300 IED attacks a month outside Iraq and Afghanistan. The powerful remote-controlled IED that killed 13 people in Algeria in June is thought to have been based on designs from Iraq, and many think it just a matter of time before the devices appear in large numbers in the West. Homeland security companies in America are already offering "IED awareness training" to emergency crews and say the global market in fighting the devices could be worth $23bn by 2012. ·