In general the size of Gaza City and its environs matches well with Mosul. Each has around two million residents in a large urban area. The challenge for Israel and for the Iraqi army were similar. The enemy was hidden among civilians and in civilian areas. ISIS had several years to fortify Mosul, while Hamas had almost two decades. In both cases the armies that were arrayed to defeat the terrorist group had to find a way to get civilians to move out of the way of the fighting.