The battle for Raqqa, Syria, seemed like a perfect storm of strategic and operational challenges. When the city was finally liberated from the Islamic State of Iraq and Syria (ISIS) in October 2017, 60 to 80 percent of it was estimated to be uninhabitable. In fact, the battle for Raqqa is a cautionary tale about civilian harm in 21st-century conflicts. The purpose of this report is to discuss how the U.S. military-which is the best-trained and most technologically advanced military in the world, is supported in Operation Inherent Resolve by an international coalition of more than 80 countries, and was partnered in Raqqa with a well-respected militia force on the ground-could cause significant civilian harm despite a deeply ingrained commitment to the law of war. In this report, RAND researchers study the causes of civilian harm in Raqqa and provide insights into how the U.S. Department of Defense (DoD) can reduce civilian harm in future operations.