Scenes from Monday's battle provide a tentative but valuable glimpse into the evolving role of special operations troops and how that might be playing out on the ground in Iraq.

Kurdish forces had once held Zumar but lost control of the town in early August in the same ISIS offensive that drove tens of thousands of Yazidis into the mountains, fleeing massacres at the hands of the Islamist militants. As ISIS advanced, besieging religious minorities and driving the Kurds into retreat, President Obama expand the military mission in the country and authorized airstrikes against the group. The effect of U.S. airpower has been clear, pushing ISIS back and allowing Kurdish and Iraqi security forces to regain territory.