Random observation of the day

I have heard, over the past 3 years, many pundits and commentators of all ilks express amazement at the barbarity of the Muslims who kill each other for sectarian reasons. The argument goes 'I can understand them hating the Jews and maybe even the Christians but what kind of religion turns on its own kind' or some close approximation of that. This is generally used to show what a backwards religion Islam really is.

The only response I can think of to this is, 'Has anyone ever heard of Northern Ireland'?