While eyes have been focused on Sunni extremists and their lightning campaign across Iraq, there is a much more fundamental war raging behind the scenes.
It is a clash between two arch-terrorists: the head of al-Qaida's central operation, Ayman al-Zawahri, and the man leading the Sunni extremist charge in Iraq, Abu Bakr al-Baghdadi.
The outcome of the battle between the two men could fundamentally change the face of terrorism.
The dust-up between Zawahri and Baghdadi broke out in the open earlier this year, and it centered on territory.
Zawahri wanted Baghdadi to limit his ISIS operati