President Obama could end his presidency with a crisis in Iraq of his own making.
In April, the president said the conditions for liberating Mosul from the Islamic State should be in place by year's end. But Sunni Iraqi tribal leaders and Kurds are quietly warning that "doing Mosul" is likely to result not in military victory but a humanitarian and political disaster.
First, Iraq's second-largest city is home to 1 million to 2 million people. ISIS, which hasn't hesitated to slaughter fellow Arabs and flatten cities, has had ample time to prepare to take hostages and booby-trap buildings.
Consider the Iraqi government's recent "victory" in Ramadi, with a population far smaller than Mosul. ISIS virtually flattened it before being ousted in January. ISIS is even more deeply embedded in Mosul, which it has occupied since June 2014. Its fanatics haven't hesitated to use chemical weapons in Syria and against Kurdish peshmerga forces.
An offensive would spread panic among the city's beleaguered residents, who would be trapped inside Mosul along with their occupiers. Baghdad's plans to liberate the city include strangling ISIS by laying siege to Mosul in preparation for a full assault. If Ramadi is any example, liberation could turn Mosul into an uninhabitable ghost town.
Second, Mosul's Sunnis still distrust Baghdad. Many fear Iraq's semi-independent Shiite militias, some backed by Iran and encouraged by former Prime Minister Nouri al-Maliki, pose a greater long-term threat to them than ISIS. Horrific images of Shiite militia-inflicted atrocities vie on Sunni smartphone screens with ISIS's beheadings and corporal punishments. Every family has a relative whom the militias have brutalized and killed.
Third, even if the US-backed Iraqi forces succeed in expelling ISIS from Mosul, then what? Who will occupy and administer the city? After the US occupation of Baghdad in April 2003, American officials gave Sunnis little stake in the planning for and future of a post-Saddam Hussein era. Why should Mosul's Sunnis believe that the chaotic central government in Baghdad has their interests at heart? Many Sunnis continue to view the 2007 "surge" as a "bait and switch" by Washington, at their expense.
Fourth, Iran seems determined to continue fomenting conflict within Iraq as long as possible. Qasem Soleimani, the head of the Iranian Quds Force who fought against Iraq during the Iran-Iraq war in 1980-1988, has greater control over some militias than the nominal political leadership in Baghdad. Few Sunnis in Mosul believe that Baghdad can protect them.
Fifth, chaos in Mosul could trigger even greater chaos in Baghdad. Iraqi Prime Minister Haidar al-Abadi seems to be trying to limit corruption and run a more inclusive regime. But trying to reclaim Mosul before Sunnis derive benefit from his efforts is risky, and American officials have signaled deep concern about the Abadi government's stability.
No strong Sunni voices in Mosul have expressed support for the invasion/liberation of their city by Iraqi forces. They know all too well America won't be there to protect them. Many continue to see the growing influence of Iran and its surrogate militias as a longer-term threat to their survival than ISIS, particularly given the nuclear deal with Iran, yet another signal of America's realignment in the Middle East.
Obama faces a tough choice, perhaps more consequential than his decision to launch the raid that killed Osama bin Laden. Should he try to encourage Iraqi forces to retake Mosul before leaving office to claim another victory over the radical jihadis he has vowed to "degrade and destroy," or encourage Baghdad to wait until a more cohesive government is in place?
While reclaiming Mosul would enable Obama to claim yet another "legacy" achievement, liberation of the city under current conditions is likely to result in more bloodshed, higher casualties, greater destruction and the creation of thousands more refugees in Iraq — a tragic, but utterly predictable coda to the Obama presidency.
Charles Duelfer is the former special adviser to the CIA for Iraq's weapons of mass destruction who led the Iraq Survey Group's hunt for WMDs. Judith Miller is a fellow at the Manhattan Institute and author of "The Story, A Reporter's Journey."