It's not crazy at all. My own reading confirms your contention, in my mind at least.
Irrational brutality is much more prevalent in arid regions, or so it seems to me, based on what I've read. Maybe it's a sort of unconscious,
instinctual desperation, brought on by life spent in conditions that are very nearly unlivable?
Much of what I'd like to contribute to this discussion, I simply can't, because this is a family site. The pages of history are worse than any
splatter film, more horrifying than the better part of De Sade's literary legacy - it's even enough to make me grimace and I'm as jaded as they
come.
When reading historical and literary accounts of Persian, Middle-Eastern, and Asian atrocities, there is a definite jingoistic tendency on the part of
European authors, who have no qualms about demonizing their subjects. That has to be taken into account, but I think there's plenty of corroboration
to go around, often coming from the accused themselves - in the form of folktales and religious tracts, tales of 'valour' and warnings delivered to
infidels, even paintings and photographs in some cases.
I definitely won't go into details, except to suggest an investigation into the practices of the Ghouls of the Sahara, or the Afridi torturers, or
the Pathans, or the Turks during the Crimean war - if one has a strong stomach, and curiosity to match. Going farther, you could investigate the
reputation of ancient Egyptian mariners, Moghul warriors, Persian slave-owners, Hindu princes like Nana Sahib, and of course there are more examples,
so many more. It would fill volume after volume if I attempted to list them all. (One day I may do just that, and will likely be labeled a
gore-nographer for my trouble
)
It's entirely possible that my reading has been slanted, and that I've acquired a false picture of history. But I think the picture is fairly
accurate. Hot, dry regions seem to produce the most insane human beings that one could possibly hope to find.
I'm also biased on account of my heritage being all snow and ice.