Iraqi special forces are on the outskirts of Mosul, poised to recapture the embattled city from ISIS. If successful, the operation will free Iraq's second-largest city from the militant group's control. ISIS has held Mosul since 2014.

But managing the aftermath will be crucial to ensuring the long-term success of the mission, said Charles Sennott, executive director of The GroundTruth Project.

"This operation was months in the planning and being executed quite effectively, as was predicted," he said. "But what's important to understand is even if you have very effective counterinsurgency campaign and counterterrorism campaign, you go in and execute all your goals, that doesn't mean it's over."

Sennott said it will be particularly difficult to navigate the divide between Sunni and Shia Muslims in the area. While the Iraqi militia is predominantly Shia, the residents of Mosul are mostly Sunni. 

"What you're still dealing with is a very serious situation of a Sunni population inside Mosul that fears the Shia-led government," he explained.

"When the Shia militias come in, the Sunni population in Mosul wonders, 'wait a second, what's going to happen to us? The Shia don't like us very much,'" he said. "They're going to feel caught in the middle and they're going to feel scared and that's the really big battle in Iraq and in the region," he said.

To hear more from Charles Sennott, tune in to Boston Public Radio above.