First, we lack a good grasp of the motivations of those who fight for or alongside ISIL, so we assume that they are motivated by Salafism and the desire to live in a caliphate. What information we do have comes almost entirely from ISIL propaganda and recruitment videos, a few interviews, and the occasional news report about a foreign fighter killed in battle or arrested before making it to his or her destination.

Focusing on doctrinal statements would have us homogenizing the entirety of ISIL’ military force as fighters motivated by an austere and virulent form of Salafi Islam. This is how ISIL wants us to see things, and it is often the view propagated by mainstream media.

For example, CNN recently quoted former Iraqi national security adviser Muwaffaq al-Ruba‘i as claiming that in Mosul, ISIL was recruiting “Young Iraqis as young as 8 and 9 years old with AK-47s… and brainwashing with this evil ideology.” A Pentagon spokesman is quoted in the same story as saying that the US was not intent on “simply… degrading and destroying… the 20,000 to 30,000 (ISIL fighters)... It’s about destroying their ideology.”

The problem with these statements is that they seem to assume that ISIL is a causa sui phenomenon that has suddenly materialized out of the thin ether of an evil doctrine. But ISIL emerged from the fires of war, occupation, killing, torture, and disenfranchisement. It did not need to sell its doctrine to win recruits. It needed above all to prove itself effective against its foes.

In Iraq, the cities that are now controlled by ISIL were some of those most resistant to American control during the occupation and most recalcitrant in the face of the newly established state. The destruction that these cities endured seems only to have hardened their residents’ defiance. Fallujah, the first Iraqi city to fall to ISIL, is famous for its devastation during US counterinsurgency operations in 2004. It still struggles with a legacy of rising cancer rates, genetic mutations, birth defects, and disabilities blamed on depleted uranium in American munitions.

In Mosul, many of those who joined ISIL last summer had been previously imprisoned by the Iraqi government. They numbered in the thousands and included peaceful protesters who opposed Prime Minister Nuri al-Maliki’s increasingly authoritarian rule.

The situation in Syria is not entirely different. ISIL emerged on the scene after a long period of strife that began with peaceful protests in 2011 and deteriorated into civil war after President Bashar al-Assad’s military and security forces repeatedly deployed brutal force against the opposition.

A large number of ISIL fighters in Syria (as in Iraq) are indeed foreign, but the majority are local recruits. The emphasis on ISIL’ Salafi worldview has tended to obscure the many grievances that may motivate fighters to join an increasingly efficient militant group that promises to vanquish their oppressors. Do they need to “convert” to ISIL’ worldview to fight with or for them? Do they need to aspire to a caliphate, as does ISIL leadership, in order to join forces with them? These questions are never asked, and “beliefs” are made simply to fill the explanatory void.