In his book Fear God and Take Your Part, 1916, Theodore Roosevelt wrote:
“Christianity is not the creed of Asia and Africa at this moment solely because the seventh century Christians of Asia and Africa had trained themselves not to fight, Whereas the Moslems were trained to fight.
Christianity was saved in Europe solely because the peoples of Europe fought.
If the peoples of Europe in the 7th and 8th centuries, and on up to and including the 17th century, had not possessed a military equality with, and gradually a growing superiority over the Mohammedans who invaded Europe, Europe would at this moment be Mohammedan and the Christian religion would be exterminated.”
Theodore Roosevelt continued:
“Wherever the Mohammedans have had complete sway, wherever the Christians have been unable to resist them by the sword, Christianity has ultimately disappeared.
From the hammer of Charles Martel to the sword of Jan Sobieski, Christianity owed its safety in Europe to the fact that it was able to show that it could and would fight as well as the Mohammedan aggressor.” - THEODORE ROOSEVELT
Enclaves of Christians and Jews survived in Baghdad, Damascus and other places, I am just curious how that happened.