stuey - //And Catholicism and Protestantism had nothing to do with "The Troubles". //
Throughout history, small pockets of evil people have latched onto causes in order to behave appallingly - often religious causes.
From the Crusades onwards, this has been going on, and it is common sense to acknowledge that the banner of the 'cause' is something on which tenuously to hang inexcusable behaviour that would otherwise lack even the pretence of a valid reason.
This is simply one more reason for terrorism.
Isis want power, and control, and destruction - they are not true Muslims, but they use that pretence to theoretically explain their crimes.
We should know better than to fall into the trap of believing that religion is anything to do with what they want - and how they go about trying to get it.