What past events led to Muslims' hatred of Christians?

Not all Muslims hate Christians, in fact on at least two
occasions (the Hapsburg Valois War and the Crimean War) Islamic nations allied with
Christian European nations against other Christian European nations. There has been,
however, a deep distrust between the two religions that has been exacerbated by historic
events.  A tremendous amount of resentment resulted from the First Crusade, when
Christian soldiers slaughtered Islamic men, women and children wholesale. So many were
killed that the horses of the knights lost their footing in the blood.  President George
W. Bush made the mistake of identifying the war on terrorism as a "crusade." Osama bin
Laden picked up on this immediately and has frequently referred to the U.S. as "Crusader
America."

United States support of Israel has also been an
issue; as it is now the Palestinian people--who were in the land before the Jews--have
been dispossessed. Their occupation of the land predates the occupation spoken of in the
Old Testament. Palestine literally is "land of the Philistines." They believe history is
on their side, and the U.S. support of Israel supplants that
history.

Finally, there is the fact that Muslims consider
Christianity an imperfect religion. They believe that the world rejected the message of
God sent by Jesus, so God sent another prophet, Muhammad, as the last true messenger.
Since Christians do not accept Muhammad and his teaching, the belief is that the
Christian religion is incomplete, somewhat similar to Christian attitudes about
Judaism.