By Saphora Smith and Michele Neubert, NBC News The Islamic State’s so-called caliphate ends 2017 in tatters. But after a year in which U.S.-backed forces drove ISIS militants from strongholds in Iraq and Syria, the group is far from defeated. Analysts warn that ISIS is retreating into what some call a “virtual caliphate” from where it … Continue reading ISIS Will Remain a Threat in 2018, Experts Warn (Learn More, Videos)