This article was originally published by War on the Rocks on 12 March 2018.
Nearly three years on from the Islamic State’s high water mark in the summer of 2015, there are several lessons that the United States and its allies can discern from the terrorist group’s meteoric rise to control large parts of Iraq and Syria to the loss of its physical caliphate late last year. The steady decline in ISIL’s fortunes is striking given the palpable fear its rise in the summer of 2014 sparked across Washington, when a common question circulating within the policy community was whether Baghdad itself might fall. Many of these takeaways will be relevant to U.S. policymakers as they attempt to prevent the group from reconstituting itself in the coming months.