Iraq is getting a fresh influx of up to 300 U.S. troops. And while they “will not be returning to combat,” as President Obama said Thursday, they will be taking on a role advising their Iraqi counterparts from the sidelines. What’s that mean exactly? Special Operations troops say a big part of the job will likely be providing command-and-control expertise, along with advice on how to integrate ISR (intelligence, surveillance and reconnaissance) feeds to allow for better intelligence-sharing. Command-and-control entails using service members assigned to use communications gear to connect combat troops with higher command, while ISR refers to various...