ABSTRACT
WATER is the controlling factor of communications in a naturally arid land. The two great rivers of Iraq have therefore always formed the natural routes for migration and conquest between the Mediterranean and the Persian Gulf. From either flank land-routes come in, from water-point to water-point across the desert, or along perennial streams which issue from the Kurdish mountains. Thus the chief aids to movement in the past have been river-craft, the camel, and the horse.
