On the twenty-fifth anniversary of September 11, Britain's MI5 Director General Ken McCallum offered a warning aimed not at the past but at the horizon: the gravest error an intelligence service can make is to perfect its defenses against a threat that has already passed. Writing in the Independent, McCallum argued that the fragmentation of modern infrastructure across private hands, combined with state-backed sabotage and persistent extremism, has created a security landscape that no single institution can navigate alone. His message was less a commemoration than a call to humility — an ackno