Islamic State militants have taken control of key cities in Iraq’s western province of Anbar and have begun to besiege one of the country’s largest military bases in a weeklong offensive that’s brought them within artillery range of Baghdad.

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.” […]