Speaking of edu books, I found this one last week (free download at Baen: https://www.baen.com/caliphate.html). Very interesting.

Part of a synopsis:

"Slavery is a part of Islam . . . Slavery is part of jihad, and jihad will remain as long there is Islam." —Sheikh Saleh Al-Fawzan, author of the religious textbook At-Tawhid ("Monotheism") and senior Saudi cleric.

Demography is destiny. In the 22nd century European deathbed demographics have turned the continent over to the more fertile Moslems. Atheism in Europe has been exterminated. Homosexuals are hanged, stoned or crucified. Such Christians as remain are relegated to dhimmitude, a form of second class citizenship. They are denied arms, denied civil rights, denied a voice, and specially taxed via the Koranic yizya. Their sons are taken as conscripted soldiers while their daughters are subject to the depredations of the continent's new masters.

In that world, Petra, a German girl sold into prostitution as a slave at the age of nine to pay her family's yizya, dreams of escape.