John Hawkins has written a piece identifying 7 Things Every Moderate Muslim Should Believe. He notes that the actions of Muslims around the world including "crazed riots over damaged Qurans, terrorists who've murdered people in the name of Allah and violent threats over Muhammad cartoons" have caused unfair suspicion to fall on all the "good and decent Muslims".
In that article, Hawkins says the following:
But, let's also stop ignoring the obvious fact that the Islamic faith has a large, radical and violent contingent that the world's other great religions don't have. Oh, but what about the Crusades? Well it's true that the Crusades were bloody, violent and directly connected to the Christian faith. However, the last crusade ended more than 700 years ago. That same sort of fanaticism has largely died out in Christianity while it's still alive and kicking in Islam.That statement is good as far as it goes, but it ignores a lot. What should be noted about the Crusades is this: The Crusades were a response to Islam's invasions — not just of the Holy Land and major parts of Asia and Africa, but also of Europe where Muslim armies conquered Spain and reached as far as Vienna before being stopped. Retaking Jeerusalem may have been the symbol, but stopping the conquest and halting the invasion was the key goal. And it should be noted that it took a long time for the Christians to begin to respond to the Muslim invasion.