They can definitely hide in the population. Rakka still have 200,000 people living there. I have no idea which part of that population are hardcore isis member : 40-50k maximum maybe. Assuming you could take Rakka, you can&#x27;t just execute or deport every one with a weird accent. Mosul is even bigger.<p>How many ground troop would it take to occupy all these cities ? This would be a repeat of the second Irak war, or Afghanistan, with the endless terrorist attacks, IEDs, etc.<p>Even if you have contributions from Kurds, Irak regular army, or Hezbollah, they would not be welcome as savior in Sunni&#x27;s territory.<p>Like in most conflict, the military option can be used to create conditions for a political resolution, but you have to provide some sort of long term plan for Sunni population : you can&#x27;t just tell them they will go back under Assad rule they despise in the first place. Currently, I don&#x27;t believe there is a clear political solution. In this condition, the military option is doomed to fail.