The Islamic State and its tribal allies have dominated Anbar since a surprise offensive last December, but this week’s push was particularly worrisome, because for the first time this year Islamist insurgents were reported to have become a major presence in Abu Ghraib, the last Anbar town on the outskirts of the capital.

“Daash is openly operating inside Abu Ghraib,” according to an Iraqi soldier, who used a common Arabic term for the Islamic State. “I was at the 10th Division base there two days ago, and the soldiers cannot leave or patrol,” he said, asking that he be identified only as Hossam because Iraqi soldiers are barred from speaking with foreign reporters. “Daash controls the streets.”

Hundreds of miles to the west, Islamic State forces continued their push into the Syrian Kurdish city of Kobane, where it appeared unlikely that Turkey would intervene to stop the advance. Kurdish officials from the town said the Turkish government had yet to respond to their pleas for weapons, and reports from the Turkish-Syrian border said there was no evidence Turkey was preparing to take action.