Earlier this week Iraqi Prime Minister Haider al-Abadi declared Mosul freed from the forces of the self-styled Islamic State, the result of the longest and most destructive urban battle of the 21st century. Elsewhere in Iraq, the Islamic State is close to losing most of the territory it once controlled. Across the border in Syria, the U.S.-backed Syrian Democratic Forces are driving the group out of its stronghold in Raqqa. Soon it may lose Deir Ezzor, the last urban center it controls.
While this is all good news, the Islamic State is far from eradicated. Many of its foreign fighters are returning home, possibly taking terrorism back with them. Some of its leaders and fighters remain in Iraq. As analyst Renad Mansour observed, “the group is resorting to guerrilla warfare, including attacks against civilians in densely populated areas of Iraq.”
This means that the United States must now make its next move, hopefully avoiding the mistakes of the past while doing so. A few years ago, when Iraq seemed to have defeated its internal extremists after the 2007 “surge” of U.S. forces, the United States withdrew its military. Then-President George W. Bush set this in motion, signing a status of forces agreement with Iraq that called for the removal of all American combat troops by 2011.