The Mosul offensive is now two weeks old. How’s it going? Contrary to Donald Trump’s claims that it is turning into a “total disaster,” it actually seems to be making steady progress.

Faced with an onslaught of some 30,000 Iraqi troops, Kurdish Peshmerga, and Shiite militias, the ISIS fighters still in and around Mosul–numbering as many as 7,000 men–have responded in predictable if not particularly effective ways. They have tried to launch suicide bombers in vehicles against the attackers, but that tactic doesn’t work so well against a force equipped with tanks and anti-tank rockets.

Marginally more effective was ISIS’s attempt to stage a diversionary raid on Kirkuk, the large Kurdish-controlled city in northern Iraq. This was a surprise attack reminiscent of the one that ISIS launched on Mosul itself in 2014. The attack failed because this time around there was no uprising of Sunni Arabs in favor of ISIS and the Kurdish Peshmerga did not scatter the way that the demoralized Iraqi army did in 2014. After several days of heavy fighting, the attack was repulsed. According to Michael Gordon of the New York Times, 84 attackers were killed along with “43 police officers, 33 Peshmerga and other security force personnel, and 21 civilians.” Another “265 people were wounded.”

ISIS is now retreating into Mosul itself, with the attacking forces hard on their heels. ISIS fighters aren’t going alone. They are seizing thousands of hostages from among civilians living in villages around Mosul and are herding them into Mosul to use as human shields. Anyone who resists is killed on the spot. This is a cruel tactic that is in violation of all the lands of land war–not that ISIS cares. But while it will inflict more unnecessary suffering on the people of Iraq it is likely at most to slightly delay ISIS’s final defeat in Mosul.

Indeed, there are now reports that Iraqi commandos, who are always on the leading edge of any assault, have already entered the city limits of Mosul. More hard fighting lies ahead, but the end is coming into sight for Islamic State’s domination of Mosul.

That doesn’t mean there isn’t still cause for considerable concern. There is–and those concerns go beyond the casualties that will inevitably be suffered by attacking forces and civilians as they clear out the ISIS dead-enders.

The first concern is what will happen after ISIS is evicted? Will the government of Iraq be able to establish a political order that will win the support of Sunnis? Or will Baghdad try to impose a Shiite domination that will lead to the rise of ISIS 2.0?

The early signs are not encouraging. The Shiite militias–the Popular Mobilization Forces–are playing a prominent part in the offensive. “Gun trucks and humvees streamed north on a highway heading to Mosul on Sunday flying the banners of Shi’ite militias along with Iraqi flags while blaring religious songs,” Reuters reported. “Although it reports officially to Prime Minister Haider al-Abadi, the coalition is mostly made up of groups trained by Iran and loyal to its Supreme Leader, Ayatollah Ali Khamenei.”

This is a serious concern because the Popular Mobilization Forces have a disturbing record of abusing Sunnis in areas previously cleared of ISIS. As Reuters further notes, “The U.N in July said it had a list of more than 640 Sunni Muslim men and boys reportedly abducted by Shi’ite militiamen in Falluja, a former militant stronghold west of Baghdad, and about 50 others who were summarily executed or tortured to death.” Amnesty International says that the Shiite militias have committed “serious human rights violations, including war crimes.”

Unfortunately, the support the U.S. is providing to the Mosul offensive in the form of airpower, artillery, intelligence, logistics, and advisers is going not just to the lawful Iraqi army but is also helping the Shiite militias. That is not a recipe for long-term stability.

The second concern is what happens after ISIS loses its last stronghold in Iraq. Inevitably it will be chased out of its Syrian capital, Raqqa, too–although that may not happen anytime soon. What then? There are plenty of signs that ISIS is preparing to shift its focus from defending its “caliphate” to staging terrorist attacks abroad. The U.S. and other Western countries will have to redouble their vigilance to prevent more bloodbaths like those in Orlando, Nice, and Paris.

But destroying the Islamic State is better than allowing it to exist, and the Mosul offensive is a welcome indication that Islamic State’s days as a territorial entity are numbered.