25 Years On, the World Is Still Learning Hard Lessons from 9/11

A quarter century after the September 11 attacks, their impact continues to shape global foreign, security, and intelligence policy. The attacks prompted sweeping changes in how governments approach counterterrorism, surveillance, and international cooperation. Despite significant reforms, analysts suggest that key lessons from the failures exposed by 9/11 are still being absorbed and applied. The BBC's security correspondent examines how the events of that day remain a defining reference point for an entire generation of policymakers and intelligence officials.