Improvised explosive device (IED) is a bomb that is homemade or otherwise put together by an amateur. Unlike military bombs, IED’s are not made using standard industrial processes. They often make use of homemade explosives, but some IED’s contain found or stolen military explosives. Terrorists and guerrilla fighters, lacking military-grade weapons, often make and use IED’s. They plant the explosives as booby traps along roads—where they may be referred to as roadside bombs—or in buildings. IED’s are often attached to vehicles.
An IED consists of two main parts. They are an initiating system and a main charge. The initiating system usually contains a small amount of a sensitive primary explosive. Initiating systems can be triggered in various ways, such as with trip wires, pressure plates, and electronic devices. When the initiating system’s primary explosive detonates, it creates a shock wave. This shock wave, in turn, sets off the main charge, also called the secondary explosive. This charge provides most of the weapon’s explosive energy. Some IED’s require a booster that helps set off the main charge by amplifying the primary explosive’s shock wave.
Early in the Iraq War (2003-2011), Iraq’s government collapsed. As a result, stockpiles of military explosives became widely available to militant groups. They used such explosives as the main charges in IED’s, combining them with homemade initiating devices. Later in the Iraq War—and throughout the Afghanistan War (2001-2021)—militants used IED’s with homemade main charges. Such explosives varied by region. Many of them employed chemicals used in local agriculture.
