Bored (when not annoyed) by facts, the president referred to the Crusades and the Inquisition as evidence of the horrors religion can wreak.

That kind of talk emboldens the Islamist line that Christian bad behavior justifies the Middle East’s bad behavior even today. The president knows as little about history as he does about warfare, and even less about religion. But he’s not alone.

With the Left’s successful destruction of history instruction in our schools and universities, even “well-educated” creatures of Washington accept the Arab fantasy that the cultural incompetence, practical indolence, and spiritual decay of the entire Middle East stems from Richard Coeur de Lion’s twelfth-century swordplay.Stop it!

All of you! And try reading a book or two on the subject. Meanwhile, here’s a starter course in the vast tragedy jihad has posed for every civilization it’s touched for the past 14 centuries — while the Crusades mythologized by Islam’s apologists were a two-century blip whose only practical legacies are a few ruined castles.Responding to the conquest of Christianity’s birthplace and jihad’s westward thrust, the Crusades were an effort not at imperial conquest but at reclamation.

By dumb luck more than strategy, the First Crusade reached the Holy Land amid local Muslim squabbles. The Crusaders took Jerusalem and made a bloody mess of it, then held the city for less than a century. They never took nearby Damascus, but were confined to a narrow coastal strip and a fragile principality in Anatolia.

During their stay, the European knights and religious orders sometimes fought each other and sometimes allied with local Muslim lords to fight other Muslims. And when Christians and Muslims squared off, the Muslims increasingly won. The damage that venal Crusaders did to Constantinople, the last bulwark of Eastern Christianity, was far worse than any harm they wreaked in Muslim lands.

And then the Crusaders were gone — and the Arabs’ real problems began. The Mongols were the ones who leveled Baghdad and shattered Arab rule in the Levant. The destruction was horrific. Millions died. The next invaders were fellow Muslims, the Seljuk and then Ottoman Turks (who would rule the Arabs for over half a millennium).In fact, the Muslim conquest of Christianity’s Middle East heartlands and the occupation of much of Europe into the 20th century did the actual damage to civilization.

Two hundred years of Crusades? How about 14 centuries of jihad? To this day, Muslims occupy every city vital to the early formation of Christianity except Jerusalem. And the last traces of 2,000 years of Christian civilization are being exterminated as we watch. Jihadis occupied most of Spain for half a millennium, and southern Spain for eight centuries.

The Islamic armies of the Ottoman Empire, whose troops went into battle shouting “Allahu akbar!” right to the end, occupied and savaged the Balkans and Greece for five centuries. Lord Byron died in the early 19th century during Greece’s struggle for freedom, and Crete escaped its Ottoman prison only at the end of that century.

The greatest symbol of Christianity’s endless suffering at jihadi hands stands in Istanbul, a city I still prefer to call “Constantinople.” The greatest surviving monument of the first thousand years of Christianity is the Cathedral of Saint Sophia — Hagia Sophia — in the city’s compelling heart. Its magnificence is haunted and haunting even today, though profaned as a museum — after the humiliation of being used as a mosque for almost five centuries, until Ataturk secularized the building.

When the Ottoman conquerors finally stormed Constantinople in 1453, the Christian knights and their families made a last stand in their beloved cathedral. The Turks, of course, butchered them, putting to death a magnificent, if fading civilization.Go there.

In a lifetime of travels, I have stood in two literally haunted spots: the compact gas chambers of Auschwitz and the vastness of Hagia Sophia. Even the huge Islamic medallions scarring the latter — a church more important to my faith than St. Peter’s in Rome — cannot put down the ghosts of 14 centuries of slaughtered, enslaved, raped, and oppressed Christians who endured Islam’s endless jihad.

And our president blames the Crusades.