A wave of Iraqi and Kurdish troops are descending on the city of Mosul with the intent of driving out Islamic State fighters who have been entrenched there for two years. Prime Minister Haider al-Abadi promised to keep up the fight until the Iraqi flag flew once again over Mosul.

When the Islamic State seized Mosul two years ago, it was a major strategic coup for the terrorist organization. With over one million people, Mosul was by far the largest city ISIL controlled then or now. It was also a huge propaganda win. Among jihadists, success always brings more followers to the fight — everybody wants to be on the strongman’s team, especially in the Islamic world. And ISIL’s victory made a mockery of Barack Obama’s handling of Iraq, proving that his withdrawal of American troops was a major blunder, yet one with which he seems perfectly comfortable.

The operational plan is the most complex assault in Iraq since the 2003 invasion to topple Saddam Hussein. Involving a total of 80,000 front line and logistical troops, the force is made up of Kurdish Peshmerga, Iraqi special forces, and a contingent of 3,000 Iraqi troops trained in Turkey.

Kurds and Iraqi forces fighting together is a feat all its own, as the two governments are frequently at odds. And there is bickering now as Kurdish and Iraqi commanders trade blame over the slowed Kurdish advance on the town of Bashiqa.

The fighting inside the city of Mosul is expected to be fierce. Iraqi troops are already preparing for a bitter house-to-house struggle. ISIL is well known for using civilians as human shields, and retreating in the field of battle often leads to execution. The invasion force purposely left a hole open in the western part of the territory in the hopes that retreating Islamic State fighters will move back into Syria. Or better still, be out in the open for U.S. aircraft to destroy.

This is not a scenario that many see as likely. Still, the hard work must be done. Kicking ISIL out of Mosul can have a stabilizing effect on Iraq.

There are caveats. Iraq veteran David French points out, “The next president will have to demonstrate a long-term commitment to Iraq’s future, and we can’t fall victim to short-term, impulse-driven politics.”

It’s hard to say if either candidate is up for this job, but any action at all will be better than what Obama has done to Iraq.