When he issued his ill-fated call to save Eastern Christendom from the Muslims around A.D. 1090, Pope Urban II unleashed what scholars across religious and ideological divides agree was one of history's biggest exercises in futility.
Over the next 200 years, wave after wave of crusading knights wrecked havoc, death and destruction at the end of which, very little was gained.
The holy city of Jerusalem was eventually recaptured by the Muslims, and experts say the only long-term outcome of the Christian Franks periodically storming the lands east of the Mediterranean Sea was an exacerbation of the suspicions and strife between Christianity and Islam.
Those were the mistakes of the Dark Ages, of course, an era when ignorance and barbarity shrouded the Western world before the intellectual illumination of the Renaissance and the Enlightenment saw reason and humanism triumph over superstition and feudalism.
But tune in to the discourse sputtering from a number of radio and TV stations across the world in recent months, and "reasonable" is not a term that will instantly spring to the average listener's mind.
By all accounts, the radical fringes within Christianity and Islam seem to have launched a modern-day crusade, a slander-to-vanquish battle where the mass media appears to have taken over from the sword as a weapon of choice.
In an interview with CBS' 60 Minutes last year, the Rev. Jerry Falwell called the prophet Mohammed a "terrorist" and "a man of war." Falwell's comments capped a TV season that saw televangelist Pat Robertson call the prophet a "robber and a brigand" and the Rev. Franklin Graham (son of the Rev. Billy Graham) denounce Islam as a "very evil and wicked religion."
On the other side, underground cassette tapes of vitriolic Friday sermons delivered by mullahs across the Muslim world are available from Cairo to Quetta. And from post-9/11 hideouts, al Qaeda continues to release taped messages promising a fight against the "infidels."
"They have taken their rabbis and their monks for gods beside Allah, and also the Messiah son of Mary," said bin Laden in a audiotape released last November. He was expanding on an earlier warning issued before the Sept. 11, 2001, attacks that the West had "divided the world into two regions — one of faith and another of infidelity, from which we hope God will protect us."
The Hot New Debate
As two Semitic, monotheistic religions (the belief there is only one God) with shared roots, Islam and Christianity have interacted for centuries, and the relationship has had its ups and downs.
If history has witnessed the Crusades, the fall of Constantinople, the ousting of the "Moors" from Spain and the Christian European colonialism that surged in the Age of Exploration, there have also been periods of confluence, when arrangements were made for Christian pilgrims to make their way to the Holy Land and scholars across religious divides were invited to debate at royal durbars, or courts.
But after the Sept. 11, 2001, attacks on the United States, whatever spotty appeal the issue of Muslim-Christian ideological harmony had in academic and public discourse quickly faded as a more pugnacious debate pitting the Muslim and Christian worlds in a "civilizational" clash suddenly made it to the top of the charts.