By nearly every metric, the Islamic State is at its lowest point in the almost five years since it declared its caliphate. The group controls no territory in Iraq and Syria, attacks are down and the number of foreign fighters it continues to recruit is a fraction of what it was at its height. But analysts who have studied ISIS since its rise in Iraq more than 15 years ago point out that the group is far more powerful today than it was when American forces pulled out of Iraq in 2011.

ISIS has adapted to its losses, returning to the guerilla tactics it used in the past, like targeted assassinations, bombings, ambushes and raids. The group still has tens of thousands of fighters in Iraq and Syria, according to United States Army General Joseph Votel. Territory that has been liberated remains insecure, as sleeper cells take root. Since last summer the group has carried out at least 250 attacks outside its controlled territories in Syria.