In the fall of 2016, I recruited a team of independent Iraqi filmmakers to help me chronicle the fall of the Islamic State. In Mosul, Iraq, as the largest urban military operation since Stalingrad unfolded, we uncovered and documented the horrific and lasting impact of a brutal reign of terror across the region.

During the nine months that our crews spent filming combat and humanitarian operations, they encountered a number of recurring themes that would be repeated time and again. In reviewing the hundreds of hours of footage that was put together for our feature documentary, "MOSUL," one thing that struck me was a sense of deep national pride and unity in the Iraqi forces’ ability and eagerness to take the fight to ISIS. Another was the underlying fear that Iraq’s history of sectarian division would pose a very real threat to the stability, security and prosperity of the nation if old hatreds reemerged.

Iraq has experienced widespread protests due to popular frustration with government corruption, foreign influence, and a lack of employment opportunities. Iraqis from all sides called for Prime Minister Adel Abdul Mahdi and his government to step down. They succeeded when he announced his resignation on Nov. 29.

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According to news reports, the government has restricted internet access in order to control the flow of information, and dissent. More than 350 people have been killed and over 8,100 wounded so far in the protests. Whoever the new prime minister will be, he will have the daunting task of ending the unrest that has dominated the country for months.

To date, the demonstrations have largely taken place in towns and cities with Shia majorities in central and southern Iraq such as Baghdad, Karbala, and Basra, and among the majority Shia population, within which there are sizable pro- and anti-Iran factions. Sunni, Kurdish and other minority communities are not thought to have been significantly involved in the uprising, nor have there been reports of sectarian violence.

Despite the seemingly obvious cause of the protests, there is much speculation as to who is inspiring the unrest and driving Iraqis into the streets. Some reports suggest Iran-backed groups; others suggest Saudi Arabia, Turkey, Israel and the United States. But the most influential actor is undoubtedly Iran, because it wields significant influence over the Iraqi government, and through its Popular Mobilization Forces, or PMFs. The government response to the protests and the actions of the security forces have only energized protesters more, causing them to become more emboldened and steadfast in their demands.

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The PMFs were instrumental in helping to defeat ISIS. However, their loyalties to Iraq have always been in question — especially as these groups have been implicated in firing on protesters, providing Iraqis even more reason to turn against Iran and its proxy militias. Many Iraqis now see the militias as a symbol and tool of Iran to repress the country.

Meanwhile, Iranian hardliners and their Iraqi supporters are growing concerned as the escalating protests threaten their influence and brand of sectarian patronage. Iranian interests have been attacked, including the firebombing of their consulate in Najaf. In October, Tehran sent the commander of the Islamic Revolutionary Guard Corps’ Quds Force, Gen. Qassem Soleimani, to Iraq to advise the government on squashing the dissent.

The deputy head of the PMFs, Abu Mahdi al-Muhandis, has called the protests a "temptation" and warned that the PMFs will intervene at a time directed by his commander in chief. However, some PMF members have pledged not to confront the protesters and attack “their own people” — implying some dissent in the PMF.

While the protests are not necessarily a sectarian battle pitching Sunni against Shia, or majority against minority, they are a battle for the heart and soul of the Iraqi street, and especially the Iraqi Shia street.

As the government struggles to quell the demonstrations, and perhaps in response to the highly publicized killings of protesters, the Iraqi Army announced that its forces have been ordered not to use live ammunition against crowds, with some commanders directing that no live ammunition will be permitted at the scene of protests. This can be interpreted as a rebuke to the PMFs, who are speculated to have been the ones firing on the protesters.

The Iraqi Army remains a somewhat respected institution within Iraq, and its Golden Division — the country’s elite counter-terrorism forces — are widely acknowledged as being the most competent. This unit was created with training and equipment provided by U.S. Special Forces; it’s manned by Iraqis with nonsectarian beliefs who come from diverse multiethnic backgrounds, and remains even now in the vanguard, fighting against ISIS holdouts.

We spent a considerable amount of time embedded with the Golden Division’s frontline units and came to respect their professionalism and dedication to Iraq. The unit had been commanded by Lt. Gen. Abdul-Wahab al-Saadi until he was abruptly relieved of his command and transferred to an administrative job at the Iraqi Ministry of Defense. This development has been perceived as being beneficial to the PMFs and Iran, as al-Saadi was widely popular across the sectarian divide and represented a unifying force in Iraq.

The decision angered many of al-Saadi’s supporters and led to demonstrations where some protesters openly displayed support for the ousted general. The Iraqi Army, especially the Golden Division, could potentially determine what happens next.

While the protests are not necessarily a sectarian battle pitching Sunni against Shia, or majority against minority, they are a battle for the heart and soul of the Iraqi street, and especially the Iraqi Shia street — a group which has been steadily infiltrated by Iran and reformed into Iran’s own brand of Shiism.

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The question remains whether Iraqi national identity and Iraq’s own brand of Shiism, are strong enough to withstand internal and external efforts to break them apart. The protests risk escalating further and drawing in other sectarian groups that would threaten the nascent national unity that had been the cornerstone of the fight against ISIS.

Despite the cautious popular optimism we encountered, there remains a sense of inevitability and resignation that the uneasy alliance that bound Iraq’s disparate ethnic groups together in their fight against ISIS is doomed to fail. In that case, the seeds of the next sectarian conflict may have already been planted.