The purity of their Islam — this is ever the basis of the jihadist appeal, and is ever ignored and downplayed by Western analysts, rather than studied so that it can be effectively combatted. From AP:
An al-Qaida front group lashed out Sunday at a key nationalist Sunni Muslim insurgent faction in a rare criticism of a follow rebel group, accusing it of betraying religion by joining the US forces in their fight against al-Qaida.
In a statement posted on at least two Islamic Web forums used by Iraqi insurgents, the Islamic State of Iraq, an umbrella groups of insurgent factions dominated by al-Qaida, called on members of the 1920 Revolution Brigades to repent during the Muslim fasting month of Ramadan.
“We call on the leaders and wise men of the (1920 Revolution) Brigades to reconsider where this path will lead them and, swearing to God, we tell them that you have betrayed your religion and the pure blood of your martyrs,” the statement said.