It's not about geography as in sands, islands, it's more astronomical as in moonbatology.
and avoids the offensive "Islamo" part
"A thing is, what it is." - Aristotle
Islam came out of the deserts of the Hejaz and its ritual language continues to be the Classical Arabic the was spoken in that region. Islamic social institutions (such as purdah) are taken from 7th cen. Arabia and are still practiced by Muslims everywhere. Hence, "Sand-Nazi" is accurate no matter where the Jihadists might be from.