Militia justice is simple, the fighters explained.

“We break into an area and kill the ones who are threatening people,” said one 18-year-old fighter with Asaib Ahl al-Haq, a Shiite militia that operates as a vigilante force around Baghdad.

Another 18-year-old fighter agreed. “We receive orders and carry out attacks immediately,” he said, insisting that their militia commanders had been given authority by Iraqi security officials. That free hand has helped make Asaib Ahl al-Haq the largest and most formidable of the Iranian-backed Shiite militias that now dominate Baghdad. […]