Battle for Mosul can shape or break Iraq further

Iraqi army gather after the liberation of a village from Islamic State militants, south of Mosul, during an operation to attack Islamic State militants in Mosul, Iraq, October 21, 2016, as toxic smoke is seen over the area after Islamic State militants set fire to a sulphur factory. REUTERS/Thaier Al-Sudan

ERBIL (Reuters) - It has taken two years of training a demoralised army, backed up by the air cover and special forces of the world’s greatest powers, for Iraq to mount an offensive to recapture Mosul from Islamic State.

Almost a week into the U.S.-led onslaught, many of those running the campaign say the battle to retake the city could be long and hard. But they have also identified what they think is a chink in the jihadists' armour.