In 636 CE, Muslim forces led by the Arab Rashidun Caliphs defeated the Eastern Roman/Byzantines at the Battle of Yarmouk, conquering Palestine...
== Western European situation ==
The western European idea of the Crusades came in response to the deterioration of the Byzantine Empire caused by a new wave of Turkish Muslim attacks...
How did the Romans/Byzantines get into Palestine in the first place? "They started it" as a historical excuse is a pretty poor rationalisation. The point is right now, in the current generation and given the current situation what is the best way to proceed.
http://en.wikipedia.org/wiki/Crusades
== Middle Eastern situation ==
In 636 CE, Muslim forces led by the Arab Rashidun Caliphs defeated the Eastern Roman/Byzantines at the Battle of Yarmouk, conquering Palestine...
== Western European situation ==
The western European idea of the Crusades came in response to the deterioration of the Byzantine Empire caused by a new wave of Turkish Muslim attacks...