Almost 17 years after al Qaeda’s attacks on America, many key questions remain unanswered. Chief among them: why did America’s National Security Agency (NSA) fail to detect and thwart the attacks? Has the NSA as an institution learned the right lessons from this national tragedy and changed accordingly? What has Congress done—or failed to do—since the attacks to improve intelligence collection while still protecting American’s constitutional rights? “The NSA and the Road to 9/11: Lessons Learned and Unlearned” brings together five former federal officials who were key players in the effort inside the NSA and on Capitol Hill to prevent the 9/11 disaster and to reform NSA’s approach to surveillance in the years after.