Excusing the actions and beliefs of islam with "b-but Christianity" is not an argument.
This right here is honestly why you should just throw in the towel now. You really don't know what's going on in the middle east if you think the religion itself is to blame for radicalization. History doesn't exist in a vacuum, after all.
Recent times, not over 300 years ago.
He's drawing parallels with historical context, dumbass. Both the Crusades and the radicalization of Islamic youth could be summed up as a political force using religion as a vehicle to gain power and territory through violence and terror, and both were written off as a dumb "Holy war" as they were happening, mis-attributing the darker purpose behind the acts and deeds to solely religious ideologies.