Turkey is learning the folly of trying to harness snakes
In its degenerate grandeur, the Umayyad dynasty that had subdued the Iberian Peninsula found itself too weak of arms and will to fight its own battles. The caliph imported fellow Muslims as mercenaries, Berber warriors whose ferocity had not been dulled by civilization. Then the Cordoba caliphate imported still more Berber troops. And more. They were, after all, fellow Muslims.Peter's point is that Turkey could suffer the same fate as it tries to deal with the terrorists it once tolerated. Pakistan is also another case in point.
But the Berbers were Muslims with a difference: fundamentalist fighters who would fit in today’s Syria. By the early 11th century, the Berber emirs and chieftains saw no reason why they should continue to serve under those whom today we would categorize as “moderate Muslims.”
In 1009, Berbers troops sacked Cordoba, then the jewel of the caliphate. In 1013, they took it again and kept it. In 1031, the fabled Ummayad dynasty faded from view.