Gains against Islamic State not yet enough, could backfire: US officials

President Barack Obama and some administration officials have hailed recent military gains against Islamic State in Iraq and Syria, but other US officials and outside experts warn that the US-backed air and ground campaign is far from eradicating the radical Islamic group, and could even backfire. While Islamic State's defeats in Iraq and Syria have erased its image of invincibility, they threaten to give it greater legitimacy in the eyes of disaffected Sunni Muslims because Shi'ite and Kurdish...