Back on Dec. 10, lawmakers wanted to know how many Iraqi troops would be needed to drive the Islamic State of Iraq and Greater Syria (ISIS) from Mosul, Iraq’s second-largest city. Brett McGurk, the State Department’s special presidential envoy for defeating the militant group, said a force of 20,000 to 25,000 would be a “reasonable” estimate of its size. Spring was the goal for the timing of the counteroffensive, assuming the Iraqi army and their Kurdish peshmerga allies had enough troops and training by then.