On March 24 the U.S. Marine Corps published photos on Facebook of its Task Force Spartan “rain[ing] steel on ISIS.” Photos showed a howitzer near Fire Base Bell near the town of Makhmur, firing at ISIS positions. Under this umbrella, a brigade of the Iraqi army was supposed to advance into six villages to begin the first stage of an operation whose goal was the liberation of Mosul, around sixty miles to the north.

According to a senior Iraqi source close to the operation, this was supposed to be a relatively easy maneuver to capture the town of Qayyara on the Tigris river. From there the army could move north towards Mosul, Iraq’s third-largest city, which has been controlled by Islamic State since June 2014. “The Iraqi army planned this because they want to change their face in front of the people and show an achievement to change the perception of failure into something good,” said the Iraqi source in a phone conversation this week.

The problem is that the main forces in the area of Makhmur are Kurdish peshmerga, part of the two-hundred-thousand-strong Kurdish forces who have been the most effective fighters against ISIS in the last two years. While the Kurds have pushed ISIS back from Kirkuk, and reconquered areas around Sinjar, liberating towns and villages, the Iraqi army has had to be rebuilt after it suffered humiliating defeats in 2014. When Iraq’s army retreated from Mosul in 2014 it abandoned many heavy weapons, and ISIS captured 2,300 U.S.-supplied Humvees as it overran numerous formations and bases.

Although both the Kurdistan Regional Government (KRG), the autonomous region in northern Iraq, and Iraq’s central government, have been fighting ISIS, the two fighting forces do not fight side by side. Add to this the fact that Mosul is a Sunni Arab stronghold and the reason it feel so easily to ISIS was due to Sunni resentment of the Shia then prime minister Nouri al-Maliki. Since last year a Sunni militia called Hashd al-Watani has been training with Turkish advisors at a base in the KRG. The Kurds would like to see a moderate Sunni Arab force re-take Mosul. Iraq’s central government relies heavily on Shia militias, such as the Hashd al-Sha’abi in its war on ISIS. Sunni parliamentarians such as Osama Nujaifi have repeatedly warned that Shia militias must not play a role in operations to liberate Mosul.

The Iraqi offensive began under that Machiavellian cloud of political considerations. The Iraqi army planned the operation without including Kurdish peshmerga, but with the Sunni militia operating alongside it and supported by coalition airstrikes and artillery. Its advance into the village of al-Nasser, overlooking the Tigris, went slowly and those present said some Iraqi troops fled. Rainy weather made air cover difficult, and the army failed to achieve minor objectives.

On Wednesday Iraq’s Defense Minister Khaled al-Obeidi toured Makhmur and admitted things were not going as planned. “Yes, that’s right, at the beginning the operation was slow and that was because we were not familiar with the area, we want to start the operation slowly to see what kind of tactics [the enemy] use against us,” he told Rudaw, a Kurdish media outlet.

The Iraqi central government has downplayed expectations for the last week, noting that it could take until the end of 2016 to retake Mosul. The problem is that the same issues the Iraqi army faced in 2014 still haunt it. The sectarian nature of this war that pits Sunnis against Shia, means Sunni resistance will stiffen if Shia militias are seen to play a role. Images distributed on an Instagram account called “Iraqiswat” reputed to show Iraqi soldiers with captured ISIS fighters, and asked the public if the prisoner should be executed. These kinds of scenes tarnish the image of the army, alongside the reports of weakened moral and soldiers abandoning positions or running at rumors of mortar fire. Kurdish forces also see the Iraqi army as receiving modern coalition-supplied equipment and wonder why Western allies are not supplying the Kurds, who have been successfully fighting ISIS, similar equipment.

In order to achieve success, it seems the Iraqi army will need to coordinate more closely with the peshmerga and the Sunni militia, and keep training its new brigades or this offensive towards Mosul is going to continue to encounter many obstacles.

Seth J. Frantzman is a Jerusalem-based journalist who holds a PhD from The Hebrew University of Jerusalem.