The Guardian and BBC Arabic just released a blockbuster story, linking David Petraeus to two veteran advisors of El Salvadorean paramilitary squads who ran Iraqi interrogation centers that exacerbated the country's sectarian violence.

It's a staggering report. According to the outlets, Colonels James Steele (in vest, above) and James Coffman (partially obscured, wearing dark glasses) both worked in El Salvador during that country's civil war. In 1986, Petraeus, then a Ph.D. candidate at West Point, traveled to the country, and "became a major advocate of counterinsurgency methods." In 2004, he was tasked with organizing the country's security forces, and Coffman became his direct report.

Coffman and Steele hired Shia to work as police commandos in detention centers — largely representatives from extremist groups like the Badr brigades. According to a former Iraqi general who worked with the men, each detention center had a committee comprised of one intelligence officer and eight men who worked as "interrogators."

[According to the general,] "This committee will use all means of torture to make the detainee confess like using electricity or hanging him upside down, pulling out their nails, and beating them on sensitive parts." There is no evidence that Steele or Coffman tortured prisoners themselves, only that they were sometimes present in the detention centres where torture took place, and were involved in the processing of thousands of detainees.

The abuse in the detention centers wasn't a very well-kept secret. Two New York Times reporters encountered screaming prisoners in one such center; in a lengthy video that accompanies the Guardian report, one Iraqi compatriot of Steele's, General Adnan Thabit, laughs when the screams are described. More ominously, Iraqi Sunnis also learned of the torture, including at least one member of the country's parliament, who was interviewed by Quicksilver Media.

Warning: this video includes graphic footage.

As Shia torture of Sunni prisoners came to the public attention, the Guardian suggests, the country's tumultuous civil war worsened. "The long-term impact of funding and arming this [Shia] paramilitary force," the paper suggests, "was to unleash a deadly sectarian force that terrorised the Sunni community and helped germinate a civil war that claimed tens of thousands of lives. "

There are other amazing details in the story: that U.S.-funded cameras were used to capture torture footage for an Iraqi TV show; that much of the information came to light thanks to the secret documents Bradley Manning sent to Wikileaks.

And this little tidbit, buried at the end of the accompanying video: Steele now works as a motivational speaker.