Roadside bombings continue to be one of the Iraq insurgency's most effective tactics against occupying forces. The public perception of the technology used is that it is improvised and crude (FrogStyle has previously featured pictures of IEDs based on artillery shells).

This is not always the case, however. It is already known that some IEDs use sophisticated technology (some of it inadvertently supplied by UK and US intelligence).

New technology, however, has been revealed by the British. "Off-route mines", which have been responsible for a number of roadside bombings targeting UK troops, are sophisticated devices that fire a "shaped charge" that can penetrate 10 cm of armour. A shaped charge is a payload, in this case of molten metal, that is given a convex shape by the explosion propelling it. The shape is designed to maximize the damage caused. UK scientists have determined that the devices are expertly machined, presumably by experienced Iraqi craftsmen.

An article in the Global Guerrillas blog has some interesting things to say about the organization and motivation of the actors involved in IED-based insurgency:

The emplacer's primary motivation is money. He is a foot soldier, is often paid as little as $50, and told to place an IED in a specific location at a specific time. A common technique is to pull a car over to the side of the road to change a tire or appear as if it's broken down. He places the IED - 75 percent of IEDs are placed in a hole previously used for the same purpose - covers it up with something, turns the switch on and drives away. Often they don't even stop, as insurgents use cars with a hole cut in the floor so they only have to slow down and drop the device onto the road.

...

The next person in the cell is the triggerman, the one who lies in wait until an American convoy passes. Often in a car, the triggerman detonates the IED either by remote trigger or command wire. Remote detonation is the preferred means, as it allows the insurgent to be further away from the blast. Captured triggermen said they prefer to hit the second vehicle in a patrol. The first vehicle passes the IED and they time it, then they hit the second vehicle. Like the emplacer, the triggerman's primary motivation is money. Sometimes these lower-level operatives will hire themselves out as a package, changing affiliations based on money.

Source: UK Telegraph