Iraqi forces face their toughest test in Mosul

IRAQ’S prime minister, Haider al-Abadi, had vowed to recapture Mosul from the so-called Islamic State (IS) by the end of 2016. In the weeks leading up to the battle for Iraq’s second-largest city, American military commanders echoed him: victory would be swift, they pledged. But with the jihadists still in control of half the city and the hardest part of the battle yet to come, these predictions now look naive.

In the rush to dislodge IS from its largest urban stronghold, Iraq’s security forces appear to have underestimated the militants’ ability to cause carnage. Although vastly outnumbered, the jihadists have used snipers, booby traps, improvised landmines and hundreds of suicide-bombers to bog down Iraqi security forces. Elaborate tunnel networks have allowed IS to escape bombing runs from American warplanes and to ambush Iraqi forces in areas supposedly cleared.