In Syria, the Islamic State is in crisis. Over the past three years, the group has managed to expand from a regional nuisance to a force with global relevance, declaring a caliphate in June 2014 that stretched from Iraq's Diyala province to Syria's Aleppo province. By doing so, it linked the two nations into a single zone of conflict and drew the attention of numerous powers, including the United States, Turkey and Russia. Today, the group maintains a presence from western Iraq to the Syria-Lebanon border — an impressive territorial spread.
But the breadth of the Islamic State's holdings in Syria is deceptive. The group's actual reach is largely limited to small, dispersed enclaves. The unbroken expanses of territory under its control are mostly empty desert. And a look at the group's three core Syrian areas — northern Aleppo province, Raqqa and Deir el-Zour — shows how the Islamic State is steadily losing ground across its scattered, self-declared empire. Together, these territories form the foundation of the group's power in the country and are critical to sustaining flows of revenue, fighters and materiel. Yet all three are under threat.
But that does not mean the Islamic State threat will be neutralized. Instead, as the group loses territory, it will evolve to survive new conditions, remaining extremely dangerous. Unable to effectively field and supply conventional fighting units, the Islamic State will turn to insurgent tactics and terrorist tradecraft to lash out at targets. Instead of focusing on controlling territory, the group will use insurgent methods to gain the flexibility and mobility needed to stage hit-and-run attacks on its enemies in an effort to gradually weaken them. These attacks will not pose an existential threat to the Islamic State's foes, but they will continue to cause massive damage. In the meantime, the Islamic State and its successors will continue to thrive so long as grievances exist among the Sunni populations of Iraq and Syria.