The calculated distance (air line) between Nasiriyah and Ash Shāmīyah is approximately 156 miles respectively 251 kilometers.
By car or train, the actual journey to Ash Shāmīyah is certainly longer, as only the direct route (as the crow flies) between Nasiriyah and Ash Shāmīyah has been calculated here.
Air line (approximately)
251 kilometers
135 nautical miles