The golden age of Moorish Spain, when Muslims, Christians, and Jews lived in peaceful harmony under a Muslim Caliph, has become a favorite reference for those promoting the fiction that Islam is capable of peacefully coexisting with Western Industrial Civilization. However, it seems abundantly clear to me that it was the Caliph's well founded fear of Islam, and his aggressive efforts to protect himself from Islamic factional violence that enabled the golden age of Cordoba, not the claimed "tolerance" of Islam.
The fabled golden age started in the new capital city of Cordoba when Ab-ar-Rahman 1 became Emir of Cordoba in 756. Ab-ar-Rahman's family had ruled both Damascus and Cordoba, but in 750 all but Ab-ar-Rahman were massacred in a brutal civil war between Islamist factions. Fearing for his life, Ab-ar-Rahman fled Syria for Cordoba. He established himself as Caliph of Cordoba, with his main interest being to recreate his vision of "heaven on earth".
The carefully ignored key factor is that Ab-ar-Rahman's traumatic experience in Damascus gave him a unique mind-set as Caliph of Cordoba. He had strong reasons to fear a repeat of the chronic Islamic factional power struggles that had slaughtered his family and destroyed the life he'd previously enjoyed in Damascus. In order to defuse the Islamic threat to himself, he set up the Jews and Christians to act as counter-balances. He mandated tolerance for the Christians and Jews not out of respect for other religions, but rather to contain and redirect the chronic sociopathic violence of Islam.
Denied the power to physically eliminate alternatives to its traditional form of oppressive theocracy, Moorish Islam was obliged to moderate itself into an attractive alternative to the competing religions. Moors drank alcohol and even developed the process for making sherry. The balance of power that kept any one of the religions from being able to impose its will on the others, resulted in constraining all three. Forced to compete with the other religions for followers, the aggressive religionists of all three religions were effectively distracted from interfering with secular government and science.
The reduced religious obstruction allowed the ancient Greek, Roman, Hindu, and Chinese knowledge that the Arabs had collected, to resurface and feed the intellectual flowering that earned the early Cordoba its reputation for enlightenment and progress. Alas, the religious tolerance and intellectual enlightenment only lasted until aggressive Islamists regained control of the Caliphate, and imposed a traditional violently intolerant Islamic theocratic state. They restored the persecution of Christians and Jews, and quickly killed off the enlightenment that had briefly flourished in the temporary absence of religionist obstruction.
The Caliphate of Cordoba broke up into dozens of Islamic kingdoms that fought each other for territory and resources, while launching jihads against their non-Muslim neighbors in order to redirect the discontent of their oppressed populations. The jihads eventually forced the disjointed Christian kingdoms to unite behind their most aggressively militant factions in order to defeat the militant Islamics who now dominated what had briefly been the tolerant multicultural AL-Andalus
The lesson the world should take from the brief glory and ultimate tragedy of Cordoba is that Islam can appear to be tolerant when forced to coexist with others, but it can't be trusted to stay benign. The "Golden Age" of Cordoba/AL-Andalus endured only as long as Islam was actively restrained from interfering with other religions and secular society. The enlightenment occurred in spite of Islam, not because of it.
Once the Islamists regained control, they reverted to their true nature and exposed the innate oppressive intolerance of Islam. They had to destroy the enlightenment because enlightened individuals wouldn't willingly accept the repressive theocracy the Islamists intended to impose. It didn't matter to the Islamists that they were regressing humanity back to a more primitive state. All that mattered to them was turning AL-Andalus into the kind of primitive superstition dominated culture where the compliantly ignorant masses could again be deceived into believing the religionists' claims of divine sanction.
The Christians who defeated the Moors didn't destroy the Golden Age of AL-Andalus. The Islamists had already destroyed it when they violently imposed the regressive primitivism of Arabian Islam.
The Islamists were eventually defeated, but that left the Christian world still dominated by its most aggressively militant factions. Having achieved their original mandate, the Christian militants turned their religionist violence against those whose desperate fear of the Islamists had brought them to power. What followed was an orgy of Christian religionist terror and depravity that would spread death and destruction across Europe for centuries.
There are disturbing indications that militant Christianity is enjoying a resurgence, resurrected from well deserved irrelevance by a growing belief that only by uniting behind the banner of Christian holy warriors can the free world defend itself against militant Islam.
And so the belligerently ignorant demand to repeat the mistakes of the past, utterly convinced that somehow this time it will be different...