In the Middle Ages, to help stop infighting among Christian princes in Europe, the Pope sent them on a Crusade to capture the Holy Land from the Egyptian Arabs and Turks. There were several Crusades. So when Osama bin Laden says "Jews and Crusaders" he means "Jews and Christians" because of the destruction caused by the Crusades, and the way he views the western world, especially the most Christian part of it, America.