Retaking Mosul will be tricky, costly

BAGHDAD —  It promises to be the biggest and perhaps last major battle against the Islamic State in Iraq.
Iraq’s government is setting its sights on Mosul, Iraq’s second-largest city, which has been under Islamic State control since June 2014, as its next major target. The assault is probably months away, but fierce fighting has been raging as Iraqi forces try to clear the militants from villages and towns south of the city.
The goal is to protect the Qayara air base, whic