"ISIS is not Islamic

[Mister Agenda]

I don't think it's arbitrary. Do they attend mosque every Friday even if they don't have to? Do they do their prayers and give alms? It's not hard to tell if a Muslim is devout by the same standards we apply to Christians, which is basically how much time they put into things like studying their scriptures and attending their places of worship, and how they act the rest of the time. We look askance at someone who only goes to church on Christmas and Easter and has a live-in unmarried partner who gets drunk every weekend; and says they're a devout Christian. It isn't rocket surgery, and it's not particularly arbitrary as judgments of human beings go, except at the margins (how much church do they have to miss and how often do they have to get drunk before they're no longer devout is largely a matter of informal consensus and personal taste).

We rarely require an authority to tell us how to make social judgments, I don't get what's so special about this one.

Is it a red herring that much of Daesh leadership is composed of formerly secular Baathists who were kicked out of their positions of authority in Iraq?

The red herring is the pretense that history and politics don't play a great role in radicalization regardless of the region in which it is happening. Christians and atheists behave much the same way under similar conditions, they just find different justifications for their violence. The Tamil Tigers invented suicide bombing, and they were mostly atheists. The American population has become partially radicalized to the point that a large percentage of us are eager to wipe our asses with the Constitution if that's what it takes to keep Muslims out over a fraction of 1% of the deaths that have been inflicted on Muslims by the West in recent decades.