The nation’s top military general opened the door to putting American troops back on the ground in Iraq to help defeat the Islamic State in Iraq and Greater Syria (ISIS) on Tuesday, less than a week after President Barack Obama publicly ruled out the option. But the general, Joint Chiefs of Staff Chairman Martin Dempsey, also added that Obama asked him “to come back to him on a case-by-case basis,” suggesting that the commander-in-chief could be convinced of increasing America’s military involvement.