The London Times describes how one Sunni insurgent changing sides marked a turning point in the Amariyah neighborhood of Western Baghdad.

One morning in late May, a former Iraqi military intelligence officer working as an American double agent walked up to the al-Qaeda ruler of west Baghdad. The exchange of words, then bullets, that followed has transformed the most volatile neighbourhood of Baghdad into an unexpected haven of calm.

It may, according to US officers, be one of the most significant gunfights since the 2003 invasion, and its ripples across Baghdad are bringing local Sunni and Shia men together to fight terrorists and militia in other neighbourhoods.

The showdown went like this: “Hajji Sabah, isn’t it time you stopped already?” Abu Abed al-Obeidi, a diminutive 37-year-old with a drooping moustache, tired eyes and a ready smile, said. “You have destroyed Amariyah,” he added, referring to the neighbourhood.

“Who are you?” Sabah, the Islamist emir, sneered. “We’re al-Qaeda. I’ll kill you all and raze your homes.”

“You can try,” Mr al-Obeidi said.

The emir reached for his pistol. He was faster than Mr al-Obeidi, but his Glock 9mm jammed. As he turned to run, Mr al-Obeidi emptied his pistol into his back. His assault on al-Qaeda had begun.