جاسوس ها، استراتژی ها و فرصت های از دست رفته: چگونه درس های 11 سپتامبر هنوز آموخته می شود

Spies, strategies and missed opportunities: How the lessons of 9/11 are still being learnt

Twenty-five years on, the attacks have come to define a generation of foreign, security and intelligence policy, the BBC's security correspondent writes.