I had always thought (and been told by people in country) that Saudi and the UAE and probably other nations int he ME ‘fund’ ISIS and other terrorist groups to keep them off their territory …… they bribe these organisations to stay out.
Perhaps that goes on to an extent, but how do you explain the massive insurgency and civil war in Iraq? It wasn’t spontaneous or accidental, it was Al Qaeda in Iraq, which ISIS is a spin off from. Abu Musab al-Zarqawi is thought to have been funded by Saudi, initially through Bin Laden.