Christian refugees who fled the Islamic State advance through northern Iraq said that the American action was too little, too late. They said they had been abandoned by everyone — the central government in Baghdad, the Americans and British, who invaded in 2003, and now the Kurds, who had promised to protect them. Thousands of refugees have flooded into Erbil, the capital of the Kurdistan Autonomous Region, and in particular the suburb of Ainkawa, which has become home to large numbers of Iraqi Christians who have fled sectarian violence across the country since the 2003 invasion.