According to Islam, and most prominently Salafi Islam, it is dogma that if any land was once ruled by Muslims, then it must be returned to Islamic rule. Al Qaeda justifies their terror in large part on this dogma, citing, for example, the centuries old Reconquesta of Spain as a wrong that must be righted. Less ridgid is a Muslim philosophy that buildings of worship once used for Islamic worship than must remain - or be made into - mosques. For example, Caliph Omar, after capturing Jerusalem in the 7th century, is reputed to have refused an invitation to prayer in Christendom's holiest site, the Church of the Holy Sephulchre, lest his followers use that to justify turning the Church into a mosque.
The relevant background for this post is that Muslims conquered much of Christian Spain in 712 A.D. When they occupied Cordoba, they destroyed the Basilica of St. Vincent and erected over top of it the Great Mosque. Once King Ferdinand III reconquered Cordoba in 1236, he reconverted the mosque to a Church. It has remained a church for the 800 years since.
On 2 April, during Easter holy week, 120 Muslims occupied the Cordoba Cathedral and interrupted church services to loudly pray to Allah. When asked to leave, they became violent, sending two security personnel to a hospital. The NYT covered this story, leaving out the background as well as ignoring the underlying motivations of the Muslims and the dogma upon which they acted. The blogger at Winds of Jihad has written a far reaching critique of the NYT coverage as well as the NYT's entire coverage of Islam, all in addition to an exceptional analysis of the event. Read it here.