News of the “liberation” of Tikrit, the city nearby the birthplace of Saddam Hussein, from occupation by ISIS militants two weeks ago was a welcome advance in the war to destroy the extremist group. In three disturbing paragraphs near the end of a New York Times article, however, readers learned that the Iraqi armed forces and Shia militias took no ISIS prisoners in the fight for Tikrit:  “… everywhere we captured them we killed them because they were the enemy,” explained one militia commander. As justification, he explained that all “about-to-be captured” ISIS members were potential suicide bombers. Thus, it was necessary to kill them as a precaution. Another battalion commander described the treatment his forces gave last week to captured ISIS fighters from Afghanistan and Algeria:  “After we were done with them, we killed them.”

No one questions the terrible brutality of ISIS and the need to stop the group’s advances in the Middle East. Forensic experts already are at work exhuming mass graves of ISIS victims in Tikrit. Nevertheless, it is time to consider how the United States, the Iraqi government, and other members of the coalition against ISIS can comply more fully with the law of armed conflict during this fight. The killing of prisoners is a war crime and in the campaign to re-take Tikrit, our Iraqi allies demonstrated a disregard for law and basic human rights.

It is reported that the re-conquest of Tikrit is a prelude to a much more difficult operation to drive ISIS from Mosul, Iraq’s second largest city. The United States has to do more to ensure that Iraqi forces fulfill their obligations under international law to treat captured ISIS militants and their supporters decently. A start would be a message to the Iraqi government and Shia militias that additional military aid will be conditioned on the full compliance of their fighters with the laws of war. No illusion exists that this policy will change the vicious behavior of ISIS, stimulate reciprocal humane and lawful conduct, or moderate its ideology. Nevertheless, it is necessary to affirm that the fight to stop ISIS is important precisely because our coalition is different: our values support a clearer vision of the path to human dignity and progress. That means that the United States and its allies should support the establishment of appropriate detention facilities for captured ISIS militants. 

Second, Shia militiamen and Iraqi soldiers (as well as ISIS members) who commit war crimes should be held accountable for their misdeeds. That would help to break the cycle of impunity and lawlessness that is an obstacle to peace in Iraq. Coalition governments should assist in the investigation and documentation of atrocities so that the Iraqi Government can carry out robust and fair prosecutions of persons responsible for serious crimes.

Third, the US government should take the lead now to promote and guarantee these measures. The right leadership and expertise already exist. In 2012, President Obama created an interagency body called the Atrocities Prevention Board, a response mechanism to coordinate efforts to stop atrocities. Stephen Rapp, the US Ambassador for War Crimes Issues, is a respected prosecutor and diplomat with years of experience in building accountability and the rule of law overseas. The outstanding Law-of-War experts in the US military could advise Iraqi courts, prosecutors and police on the investigation and prosecution of persons responsible for war crimes.

When the bombing campaign against ISIS began last September, President Obama told the UN General Assembly that the coalition must “dismantle this network of death.” The President’s description of ISIS was accurate. Nevertheless, when we describe ISIS with the rhetoric of evil and then deliberately look the other way when our allies commit atrocities, we become complicit – morally if not legally – in the crimes of our partners. Some might argue that this is a tough but unavoidable price to pay in the war to defeat ISIS. That simplistic view rationalizes indifference and ignores a more fundamental interest: the coalition fighting ISIS is supposed to stand for better principles and the rule of law is supposed to apply to everyone, everywhere. Even to members of ISIS in Saddam Hussein’s hometown.