One of the most pernicious positions advanced by Muslims to justify their war on the West is that it is but a defensive reaction to the Christian Crusaders who attacked the Muslim world without provocation a thousand years ago. Osama Bin Laden and other Muslim terrorists invoke this argument by calling Americans "Crusaders." This Muslim position is unskeptically accepted by the politically correct. For example, Bill Clinton declared that the Crusader's sack of Jerusalem in 1099 AD was the ultimate cause of the Sep 11 attacks.
Robert Spencer rebuts this dishonest history by pointing out that long before the First Crusade launched, Muslims had conquered two thirds of the Christian world in a massive campaign of bloody religious imperialism. This and much more is laid out in his excellent book, "The Politically Incorrect Guide to Islam (and the Crusades)
After Mohammed died in 632 AD, the Muslims embarked upon a jihad to conquer the known world for Islam. The Mediterranean Sea at that time was surrounded by Christian nations. All five of Christendom's major cities came under attack by the Muslims, four of them conquered: Jerusalem, Antioch, Alexandria, Constantinople, and Rome. Only Rome barely escaped Muslim conquest after the Pope agreed to pay tribute in 846 AD.
The rules of engagement for Muslim invaders were simple, consisting of Mohammed's three part policy for dealing with unbelievers: 1) Convert to Islam; 2) Accept second-class status as a dhimmi and pay the jizya, the poll tax on non-Muslims; or 3) die.
Accepting dhimmi status meant that Muslims were the masters, non-Muslims the despised inferiors. Dhimmis must wear special clothes, give way to Muslims on the street, stand when Muslims enter a room, are forbidden to build new churches, can not bear arms, may not strike a Muslim, and their testimony has no weight in court. When a dhimmi pays his poll tax, the Muslim collector must humiliate him so that he feels subjugated, in accordance with the Koran. Typically, this means that the dhimmi must stand while the collector sits. When the dhimmi pays, the collector strikes him on the face to ensure he feels inferior. While Muslims claim they do not compel anyone to become Muslim, in practice being a dhimmi was so difficult that most converted to Islam to end the abuse.
The Muslims swept across Christian North Africa, annihilating villages who had no idea what a Muslim was until they swept into their homes and began beheading them, raping them, looting them, and enslaving them. They crossed the Strait of Gibraltar into Spain in 711 AD, most of which they conquered by 715 AD. They pressed on to invade France but were stopped by Charles Martel at Tours in 732 AD. Two more unsuccessful invasions were attempted in 792 AD and 848 AD.
On the other end of the Mediterranean, the Muslims conquered the Christian city of Jerusalem in 638 AD. They swept north to Christian Syria and Armenia and then into Byzantine Asia Minor (modern Turkey). The Muslims laid seige to Constantinople, the capital of Christian Byzantium, in 668 AD and 717 AD unsuccessfully. The Muslim war went on for nearly three and a half centuries before they conquered all of Asia Minor. It took until 1453 for the Muslims to conquer Constantinople and rename it Istanbul.
The Muslims also attacked through southern Europe, raiding Cyprus, Rhodes, and Crete. They invaded Sicily in 827 and pressed on into Italy, reaching Rome in 846 AD. Rome paid tribute to the Muslims, thus avoiding becoming a Muslim city. Otherwise, the Vatican would be another mosque.
By the end of the eleventh century, the Byzantine empire had been whittled away by Muslim invaders until only Greece remained. The Byzantine emperor, Alexius I Comnenus, pressed by savage Muslim armies, called upon Pope Urban II for help in his defense. Pope Urban launched the First Crusade in 1095 AD to defend Greece against the Muslims.
By the time the First Crusade was launched, Muslims had savagely conquered Christian village after village, nation after nation, penetrating Europe on three fronts, in a jihad that was waged from the initial conquest of Jersulem in 638 AD for 457 years. Yet the Muslims ignore their four and half centuries of aggression to claim the Christians had initiated hostilities with Islam with the Crusades.
Therefore, the Muslim claim to be the innocent victim of unprovoked aggression by Christian Crusaders is simply a pack of lies, lies which have become Islamic doctrine.
The Muslim jihad against the West continued until 1683, when they became too weak to continue waging large scale war. The Muslim will to wage jihad remained and the doctrine of jihad remained in force. It wasn't until oil money reinvigorated the Middle East that Muslims were able to renew their jihad against the non-Muslim world.
The Muslim jihadis operate under the same rules of engagement. Before attacking, Islamic law mandates that the infidels be issued a call to Islam. For example, Osama Bin Laden opened his war with America by calling on it to convert to Islam in his November 2002 "letter to the American people": "What are we calling you to, and what do we want from you? 1) The first thing we are calling you to is Islam ...." When the infidels reject the call to Islam, Muslims are then free to make war on them.
The Muslim doctrine of taqqiya, "concealment," allows Muslims to lie among unbelievers, especially when living in infidel nations. It is permissible to deny parts of Islam to survive. For example, you can publicly object to terror in America while sending secret contributions to Al Qaeda.
Spencer makes other interesting points about the differences between Islam and Christianity. For example, Christians believe that there is an order to the universe, which is governed by laws. For them, the universe is like a giant clockwork made and set in motion by God. The Muslims, by contrast, reject this. Their universe is governed by Allah's arbitrary will, which can change at any time. The pieces of the world need not interact rationally. In short, the Western world holds reason to be the highest virtue, while the Muslim world holds faith to be supreme.
Muslims do not agree with the United Nations Universal Declaration of Human Rights. For example, they want capital punishment for infidel murderers of Muslims but forbid it for Muslim murderers of infidels, forthrightly explaining that non-Muslims are "on a lower level of belief and conviction" than Muslims, who possess a "loftier" faith. They also disagree with the right to change religions. Islamic law demands the death penalty for apostates.
The West believes in pluralistic governments which allow all faiths to flourish. Islam demands a theocracy where non-Muslims are second-class citizens. The West is committed to democracy. Islam is committed to authoritarian theocracy. Spencer bluntly states that Islam is a totalitarian, supremacist, expansionist ideology. The difference in values between the West and Islam leads to the current clash of civilizations. Spencer quite rightly states Western values and traditions are superior and worth fighting for. We deserve to win against Muslim terror, which represents an inferior set of values.
For anyone who wants a deeper understanding, without the fuzzy-wuzzy multicultural candy coating, of the Islamist enemy who is waging war on the West through terror, I Strongly Recommend This Book. It is very readable and provides you with all the talking points you need to defeat politically correct liberals in argument.