By the time the Persian Empire that succeeded the Assyrians stepped in, it’s possible that the Persians may not have had to have been as brutal, because Assyria had already cowed many of the tribes, peoples, and states who otherwise would have posed a threat.* It’s even been suggested that the reason Alexander the Great’s invasion of Persia three centuries later seemed easier than perhaps anyone thought it would be was because the region had already been broken to the yoke of empire after centuries of wars with Assyria.
