In September 2021, the CIA recalled its Vienna station chief reportedly over his response to a series of “anomalous health incidents” experienced by over two dozen personnel. These incidents mark the latest entry in a series of mysterious afflictions more commonly referred to as “Havana Syndrome.”

Contemplating the causes and effects of 9/11, as well as the experiences of those on the ground that day, yields useful insights into tackling today’s intelligence and policy challenges. This report is derived from 9/11: Intelligence and National Security Twenty Years Later, a full-day conference hosted by the Belfer Center’s Intelligence Project that examined the impact of the 9/11 through personal stories and policy reflections. It explores how strategic intelligence on Al Qaeda’s intentions failed to lead to policy changes that could have prevented the attacks on 9/11. It also examines how the U.S. can draw on the experience of 9/11 as it faces the specter of great power competition with China against the backdrop of globalized, existential threats posed by climate change and novel disease outbreaks like COVID-19. It also explores the critical nexus between intelligence warning and policy action. More broadly, the twentieth anniversary of 9/11 is an opportunity to reflect on who we are as a nation and who we want to be in confronting violent extremism—both at home and around the world.

This report is derived from a half-day conference in April 2021 co-sponsored by the Intelligence Project and the Environment and Natural Resources Program at Harvard Kennedy School’s Belfer Center for Science and International Affairs, along with the Center for Climate and Security and The Cipher Brief. It explores the requirements of the U.S. Intelligence Community (IC) to fulfill the mission prescribed by President Biden, DNI Haines, and Secretary Kerry. The IC must rise to challenge, unshackled from the past, to re-imagine its role in combatting climate change. The IC has talked the talk about climate change, and now it needs to walk the walk. The stakes are too high not to do so.