isis raqqaRaqqa Media Center/APThis undated image posted by the Raqqa Media Center, in Islamic State group-held territory, on Monday, June 30, 2014, which has been verified and is consistent with other AP reporting, shows fighters from the al-Qaida linked Islamic State of Iraq and the Levant (ISIL) during a parade in Raqqa, Syria.
The use of car bombs in guerrilla warfare is not a new tactic, but the Islamic State (IS) has deployed an unprecedented number of them as it has fielded a more conventional force in order to capture cities in Iraq and Syria.
In contrast to their use as traps or along roadsides, IS has used vehicles rigged with bombs and improvised explosive devices (IEDs) much as the US has traditionally used air power: as a means of assaulting ground forces and opening up targets to attacks by infantry units.
"It is a very effective weapon and we have taken great efforts to advance our targeting capabilities in order to allow us to find these locations where IEDs are being produced and target them appropriately," Marine Corps Brig. Gen. Thomas Weidley, the chief of staff for the air war in Iraq and Syria, told reporters recently.
The asymmetric nature of the tactic can seem astounding — with the Pentagon spending more than $9 million a day to fight the insurgency, IS is constructing bombs virtually for free.
IS is manufacturing the weapons at an alarming rate, using everything from fertilizer to military grade explosives.
kobani syria isisREUTERS/Ali Sahin Smoke rises in the Syrian town of Kobani as it is seen from the Turkish border town of Suruc in Sanliurfa province, Turkey, June 25, 2015.