Until the advent of materialism and 19th c. dogma, Western Civilisation was superior to anything Islam had developed. Islam has not aided in the development of the modern world; in fact civilisation has only been created in spite of Islam. Proof of this resides in the 'modern' world and the unending political-economic and spiritual poverty of Muslim states and regions. Squatting on richer civilisations is not 'progress'. Islam is pagan, totalitarian, and irrational.
Seven Myths of the Crusade, is a scholarly book debunking the revisionist history in vogue since the days of Walter Scott. Revision history is a nice way of saying ignorant, mendacious, non factual history. Atheists and Protestants recast much of real history in their zeal to attack and demolish the Church. Portraying the Catholic crusades as part of the mythical 'Dark Ages' was of course, part of this general animus against pre-Protestant history [a civil war which killed hundreds of thousands, witch burnings, destruction of art, treasure and architecture, book burnings, no free will, abiogenesis etc.].
A review of the book is summarized here. Links to other myths about the Crusades are below the review.
As the editors make clear in their preface, Seven Myths of the Crusades is presented as an antidote to the "outpouring of exaggerations, misperceptions, errors, misrepresentations, and fabrications" that proliferate in popular discourse about the Crusades. In the course of seven chapters, each written by a specialist and supported by scholarly notes and fresh research, this short primer examines and exposes the many anachronisms around the Crusades.
Andrea, professor emeritus, University of Vermont, and Holt of Florida State College make their basic assumption clear from the outset stating that the notion that medieval people ... were 'just like us' and acted out of motives very much like our own ... has led to some basic misunderstandings of the crusades and the people involved in them.
While not all chapters are equally enlightening, the more useful ones deal with large and important themes including whether the Crusaders were motivated by proto-colonialist greed, irrational fanaticism, or sincere piety. Paul Crawford examines whether the First Crusade was an "unprovoked offense or overdue defense" against Islam while Mona Hamad and Edward Peters question whether modern-day Muslims actually still hold a grudge against the West because they have "a nine-hundred-year-long grievance."
Crusades were a reaction against 400 years of Fascistic Moslem Jihad.
Crusades proved the already nascent superiority of European civilization.
Crusaders did not wade hip deep in blood in taking back Jerusalem and here.
Moslems slaughtered far more innocents at various sieges from Antioch and Tyre to Constantinople.
The Crusades had nothing to do with Marxist theology around 'colonisation'.