Photographs and video appearing on social media showing American-trained Iraqi forces committing atrocities were broadcast in a report by ABC News on Wednesday. Iraqi soldiers with insignias on their uniforms belonging to units that have received American arms and training are seen in these pictures and videos holding severed heads, killing a young boy, and dragging a body by a rope. According to the ABC report, troops that have been trained for the fight against the Islamic State of Iraq and Syria (ISIS) are “under investigation for committing some of the same atrocities as the terror group [ISIS].”

U.S.-trained and armed Iraqi military units, the key to the American strategy against ISIS, are under investigation for committing some of the same atrocities as the terror group, American and Iraqi officials told ABC News. Some Iraqi units have already been cut off from U.S. assistance over “credible” human rights violations, according to a senior military official on the Pentagon’s Joint Staff.

The investigation, being conducted by the Iraqi government, was launched after officials were confronted with numerous allegations of “war crimes,” based in part on dozens of ghastly videos and still photos that appear to show uniformed soldiers from some of Iraq’s most elite units and militia members massacring civilians, torturing and executing prisoners, and displaying severed heads.

The videos and photos are part of a trove of disturbing images that ABC News discovered has been circulating within the dark corners of Iraqi social media since last summer. In some U.S. military and Iraqi circles, the Iraqi units and militias under scrutiny are referred to as the “dirty brigades.”

At Bloomberg View, Eli Lake followed up on the ABC report, providing context for the atrocities being committed.

The collapse of the Iraqi army before Islamic State in Kirkuk and Mosul in June has allowed sectarian militias backed by Iran to lead the fight against the jihadi group. In some cases, the militias — which have histories of ethnic cleansing in Iraq — are commanding Iraqi military officers.

Although this development has helped Obama keep his promise not to send large contingents of ground troops back into Iraq, it also means that the army the U.S. trained is now under the influence of Iran, which has supported and sustained the militias now accused of committing atrocities against the minority.

Now that Iranian military advisers, Shiite militias and a weakened army are leading the fight to recapture Tikrit from Islamic State, it’s strange that [Chairman of the Joint Chiefs of Staff Martin] Dempsey would talk about the potential for atrocities as a hypothetical. Atrocities are occurring, despite the new Iraqi prime minister’s commitment to a more inclusive government.

Last month, Lake reported that in Iraq’s Diyala province the army was under control of a militia figure who reported directly to Qassem Suleimani, commander of the Qods Force, the arm of Iran’s Islamic Revolutionary Guard Corps that supports allied terror groups around the world.

Lake observed that, when he was in Iraq in 2007, “Iraqi officers also behaved better because U.S. officers were fighting at their sides.”

A video of the ABC report – with disturbing images – is embedded below.

Michael Pregent observed in I Saw the U.S. Hand Iraq Over to the Iranians. Is the Whole Region Next?, which was published in the February 2015 issue of The Tower Magazine,  that the percentage of Shiites in the Iraqi forces corresponds to the likelihood that Sunnis will be targeted.

General David Petraeus had some success in reaching a balance between Sunni and Shia when he was head of Multi-National Force-Iraq (MNF-I). When he left in 2005, he left behind Iraqi army divisions in and around Baghdad that had a 55-45 percent ratio of Shia to Sunni.

Before Petraeus took command of MNF-I in 2007, I had the opportunity to brief him on the changing sectarian make-up of the ISF under his predecessor—General Martin Dempsey. The divisions in and around Baghdad were now over 90 percent Shia and mostly militia-affiliated. Petraeus was shocked.

This shift in the sectarian makeup of the security forces was the result of a 2006-2007 purge of Sunni commanders, leaving a sectarian military force that saw few distinctions between any Sunni man of military age and the Sunni insurgency. Extra-judicial killings in Baghdad skyrocketed, with somewhere between 25-50 percent of prisoners being summarily executed, and bound Sunni men dumped around Baghdad in an attempt to terrify Sunnis out of supporting al-Qaeda in Iraq (AQI) and its affiliates.

General Dempsey was in charge while this process was taking place. Asked about it by advisors and analysts, Dempsey replied, “I make no distinction between Shia and Sunnis. I only see them as Iraqis.” This was a noble position to take, and would have been correct if the rule of law had been in place and militia membership seen as a disqualification for service. But there was no rule of law, and the Sunnis did not share Dempsey’s views. This misunderstanding came at a high price. The purged and executed Sunni officers were the exact Iraqis we needed—those who were willing to fight both AQI and Shia militias at great personal risk. Now, they were targeted and killed by both of them.

[Photo: ABC News / YouTube ]