When his three-car convoy pulled up to a police checkpoint in Baghdad on Friday the 13th of February, Sheikh Qassem al-Janabi had little reason for concern. An influential Sunni moderate who was assisting the Iraqi government's efforts to draw Sunni tribes away from the orbit of the Islamic State of Iraq and Syria, the charismatic Sheikh Janabi had many friends in high places.

He was in the capital, supposedly far away from any likely ISIS assassins. And he was a longtime friend of the United States, which in the past year had sent military forces back to Iraq to counter the ISIS terrorist group. Sheikh Janabi was riding with seven bodyguards and his son Mohamed, recently returned to Iraq from earning a law degree from the University of Glasgow. They were traveling from their tribal homeland south of Baghdad on the Muslim day of prayer.

The men at the police checkpoint were impostors and suspected Shiite militiamen, and they bundled up Janabi and his entourage at gunpoint, quickly driving them away. Their bodies were later found across town in the ramshackle Shiite slum of Sadr City. Janabi was slumped in the back of one of the cars, his hands tied behind his back with his own belt, a bullet in his head. The bodies of his son Mohamed and seven bodyguards lay nearby, all of them shot execution style. To reach Sadr City, the gunmen would likely have passed through several police checkpoints, raising questions of possible official collusion in the murders.

When the history of the second Iraq civil war is written, the death of Sheikh Qassem al-Janabi may prove notable for what it said about the rapidly closing window for national reconciliation, and for foreshadowing the ominous turn toward outright sectarianism that the fighting in Iraq has taken. Certainly the Sunni lawmakers who walked out of parliament in mass protest on learning of his murder understood his importance, both real and symbolic. Along with other moderate Sunni tribal leaders who first turned against al-Qaida in 2006-07 and took part in the "Anbar Awakening" during Iraq's first civil war, Janabi rejected the terrorists' vision of a purifying civil war between Sunnis and Shiites. Instead he continued to embrace the U.S. vision of a unified and democratic Iraq until the day of this death.

When U.S. officials and military forces returned to Iraq last year, helpfully nudging aside sectarian strongman and Prime Minister Nouri al-Maliki, the question they posed was whether enough Sunni leaders of goodwill could still be found to rekindle the dream of reconciliation and create another Anbar "miracle." The ascendance of Iranian-backed Shiite militias and death squads, and the manner of Janabi's death, suggest that such hopes are tenuous. In a well-documented massacre in the eastern province of Diyala just weeks before his death, for instance, more than 70 unarmed Sunni men were killed by Shiite militiamen, and there have been numerous accounts of smaller scale atrocities by roving Shiite death squads.

Even more ominously, Iranian-backed Shiite militias are leading the Iraqi offensive launched this week to retake the Sunni stronghold of Tikrit, former home of Saddam Hussein. Multiple credible reports indicate that Iranian Revolutionary Guard forces and Shiite Hezbollah fighters are actively supporting the offensive, which reportedly is overseen by infamous Iranian Quds Force Commander General Qassem Suleimani. There are also reports that Sunni civilians in Tikrit, terrified of revenge killings and a campaign of ethnic cleansing, are fleeing north to the ISIS-occupied city of Mosul. Shiite militia commanders have promised on state television to take revenge in Tikrit for ISIS's massacre of Shiite soldiers captured at nearby Camp Speicher last June, when hundreds were executed in an atrocity videotaped and posted on YouTube.

Just as worrisome, U.S. officials remarkably insist that they were taken "by surprise" by a Tikrit offensive involving tens of thousands of Iraqi troops and irregulars. Not only were they apparently not consulted, but U.S. forces are not providing air power to the campaign. Nor are U.S. officials otherwise involved in the biggest Iraqi counteroffensive since ISIS captured roughly a third of the country last summer.

The Obama administration seems to think that reconciliation is something that they can focus on later, or just leave to the Iraqis to sort out themselves, but they are flat-out wrong. Ken Pollack, senior fellow, Brookings Institution's Center for Middle East Policy

"Bottom line, Iranian-backed Shiite militias are doing most of the anti-ISIS fighting in the Tikrit campaign and elsewhere in Iraq, and that is terrifying to Sunni populations who have heard all these stories about ethnic cleansing, both real and exaggerated," said Ken Pollack, a senior fellow at the Brookings Institution's Center for Middle East Policy, and formerly a CIA Middle East analyst. "The Obama administration seems to think that reconciliation is something that they can focus on later, or just leave to the Iraqis to sort out themselves, but they are flat-out wrong," said Pollack, who recently returned from Iraq. "This is not a theoretical issue. If this trend continues, the United States really will become the air force for Iranian-backed Shiite militias and the Kurdish Peshmerga in a sectarian civil war."

An Unlikely Ally

In retrospect, Sheikh Qassem al-Janabi was an unlikely ally. In 2004 he was an influential Sunni tribal leader in an area just south of Baghdad that was so violent and overrun by insurgent activity that U.S. commanders dubbed it the "Triangle of Death." When two foreign contractors working for the U.S.-led coalition were kidnapped by insurgents in the area, diplomats in Baghdad reached out to him for help. Janabi put the word out through tribal networks that the contractors should not be hurt, and at the request of the diplomats he worked as an interlocutor, eventually arranging a deal for the contractors to be returned in exchange for a ransom.

Only a U.S. brigade commander in the area got word of the deal, and he called Janabi in for questioning. Despite the fact that Janabi was working on behalf of coalition diplomats in Baghdad, the colonel was angry that he hadn't been tipped off to the exchange in order to arrest the kidnappers.

"Sheikh Janabi told him that would have certainly gotten the hostages killed, but the U.S. brigade commander arrested him anyway," said Rick Welch, who at the time was an American adviser in Iraq in charge of a U.S.-led tribal "conflict resolution" program that Janabi supported. "I visited Janabi in Abu Ghraib prison a bunch of times, and thought I had arranged for his release by the time I rotated back home in 2005. Then I returned to Iraq in 2007 and learned that he was still in prison! I was so furious that we Americans could be so arrogant and stupid, but I finally got him released, and we worked closely together for the next four years."

By 2011, Welch was in charge of the U.S. military's reconciliation program in Iraq, which sought to establish relationships and provide the connective tissue between Sunni tribal leaders and the Shiite-dominated government in Baghdad. After wanton slaughter by Sunni al-Qaida and Shiite death squads very nearly pushed Iraq over the abyss into an all-out sectarian civil war in 2006-07—a slide reversed only by the U.S. troop surge and the Anbar Miracle—everyone understood that reconciliation between Shiites, Sunnis, and Kurds was the only hope for a unified Iraq.

After U.S. military forces exited Iraq in 2011, however, Prime Minister Maliki began a relentless campaign to purge government institutions and the security forces of Sunni leaders, and he violently crushed the mostly peaceful protests of Sunni demonstrators that resulted. "After the U.S. forces left, Maliki knew that he was unchecked, and he looked for every excuse to violently subjugate the Sunnis, to the point where a lot of Sunni tribal leaders eventually decided that their chances for survival were better with ISIS than with Maliki's government," said Welch. And yet Janabi remained a friend of the United States and the democracy project to the end. "I was in touch with him just a few weeks before he was murdered, and he was critical of the sectarian agenda of the Iraqi government, but even more so of ISIS. He kept encouraging Iraqis who had fled the country to come back and help rebuild it."

New Prime Haider al-Abadi talks a good game in terms of inclusion and reconciliation, said Welch, but the fact that he has ceded security to Iranian proxies and Shiite militias that are the flip side of the same sectarian coin as ISIS suggests that the Iraqi leader has insufficient political and military backing. The United States has to support Abadi much more forcefully in trying to rein in the Shiite militias, said Welch, because the tentative and reactive approach that U.S. officials have taken, in comparison to Iran, is putting American friends like Sheikh Qassem al-Janabi at risk. "He was a good man, with a beautiful son, and their death sickens me. I continue to see their faces in my dreams."

A Narrow Tightrope

To date U.S. officials say that Abadi has largely lived up to his promise to form a more inclusive government and seek reconciliation with the Sunni tribes. They laud him for reaching a long-elusive deal to share oil revenue with Kurds in the north, for instance, and for agreeing to the future formation of National Guard units made up of local, indigenous troops, as opposed to having an overwhelmingly Shiite army enforcing security in Sunni areas. Abadi has also agreed to allow a more federal system of governance—permitted under the Iraqi constitution—that will give Sunni provinces more autonomy.

Until U.S. train-and-assist forces can complete the task of helping to rebuild Iraqi Security Forces decimated by Maliki's cronyism, corruption, and purges of Sunni commanders, however, Abadi has in the short term continued to rely disproportionately on well-established Shiite militias and Iranian backing. Under current plans, U.S. commanders hope to field 12 Iraqi combat brigades, but they concede that these are also overwhelmingly manned by Shiite troops.

"In the end, we have said that it's important that Iraq be for all Iraqis, but right now—no surprise—much of the Iraq Security Force in the field and available for training is Shiite, because much of the Sunni population has either departed Sunni areas, or else live under ISIS domination," retired Gen. John Allen, President Obama's special envoy for the global coalition to counter ISIS, said this week at the Atlantic Council. Abadi is trying to balance the equities of all elements of the government, Allen said, but he is in the midst of a turbulent crisis and "walking a narrow political trail in trying to ensure that all members of the government—Shiite, Kurdish, and Sunni—feel that their interests are best served in a unified Iraq."

As a senior U.S. commander in Iraq in 2007 during the Anbar Awakening, Allen knows better than most that the Iraqi government's heavy reliance on Shiite irregulars is a grave risk. If what happened to Sheikh Qassem al-Janabi is repeated once Tikrit is recaptured or in other Sunni areas "liberated" by overwhelmingly Shiite Iraqi forces, then the expedient deal that Abadi and his American backers have made with the devil could well tear Iraq apart. "How the outcome of the counteroffensive unfolds," Allen said, "how populations liberated from ISIS are treated and represented by a central government that is largely Shiite—that will determine in the end whether Iraq's Sunnis want to be part of this experiment."