This book, based on four years of on-the-ground reporting, research in ten countries in the Middle East, a thousand hours of interviews with key players and access to generals, spies, policymakers, soldiers and refugees, is the first comprehensive look at the defeat of ISIS and the future reshaping of the Middle East. It provides a unique window into the battle for the heart and soul of the Muslim world and lays out why we need to be informed about changes on the ground after the defeat of ISIS. More than seventy countries are members of the international coalition formed in 2014 to defeat Islamic State (ISIS). After ISIS provides a sobering blueprint for how the US and regional powers will re-shape the region in years to come. Understanding these events and the choices ahead will determine if ISIS and similar ideologies reemerge, whether a new war between the US, its allies and Iran comes in the wake of ISIS, or if a younger generation of leaders can carve out a new Middle East. As ISIS recedes, the world is at a unique historic crossroads in the Middle East. Decisions made now in the region and in Washington matter more than ever. Tehran and the US are increasingly on a collision course to struggle over the vacuum left behind by ISIS in Iraq and Syria.