DG Statement on the 25th Anniversary of the 9/11 Attacks
Published date: 15 Sep 2026
The following statement by MI5 Director General Sir Ken McCallum was published by The Independent newspaper on 11th September 2026.
"It is said that we all remember where we were on 9/11. It’s certainly true in my case: working in an MI5 operational team countering terrorism. Someone had switched on a television following news of a plane hitting the Twin Towers. As the second airliner struck, one of my colleagues softly said “Osama Bin Laden…,” then “I guess none of us leaves MI5 for at least a decade”.
And so it proved. My generation of MI5 officers had begun to wonder whether the nation’s need for our services might (happily) reduce following the end of the Cold War and then the Belfast Good Friday Agreement to which we had contributed so much. Instead, we threw ourselves at the monumental challenge of disrupting Al Qaeda networks bent on inflicting mass casualties and prepared to die in the attempt. A quarter of a century on, I am proud of the part my organisation played in the massive team effort to respond to that affront to humanity, protect lives, and defend values.
On the 25th anniversary, the world will pause to remember 2,977 lives brutally ended (including 67 British citizens) and untold thousands of other lives changed forever. MI5, which dedicates itself to striving to prevent atrocities, will fall silent to pay our respects to all victims. But we will also reflect: what can we see more clearly with 25 years’ hindsight? What lessons can we draw to keep the country safe today?
What strikes me most forcefully, looking back, is the relentless adaptation that was central to the 9/11 response. This remains pivotal as we contend with the still-more-complex challenges of the 2020s.
I will leave to others judgments on the overall coalition action in Afghanistan, other than to note that foreign policy, like operational counter-terrorism, is harder than many commentators allow. Focusing in on where MI5 can speak with some authority – the counter terrorism mission – the hard reality was that some form of Afghanistan intervention was necessary. The Al Qaeda which had murdered in Africa and the Gulf pre-9/11, and then brought down the Twin Towers eight years after Ramzi Yousef’s failed attempt, had no plans to ease off. Indeed quite the reverse: a string of further conspiracies was coming our way.
To meet that murderous intent on the UK home front, MI5 and the police reimagined our partnership, co-locating teams across the country. With outstanding support from MI6, GCHQ, US and other partners, multiple plots were detected and disrupted prior to 7/7. A year after that devastation came our most crucial success, when an aviation plot threatening a death toll and global shock on a par with 9/11 itself was averted – by a team of teams none of us could have imagined five years earlier.
Al Qaeda had to be not just taken on, but taken down. A gargantuan multinational effort, powerfully spearheaded by the US, devised new capabilities to dismantle the core of the organisation in Pakistan’s Federally Administered Tribal Areas, into which it had been pushed by the Afghan campaign.
It worked. Al Qaeda remains a threat today, but its capabilities are a fraction of 2001’s. That rolling back was not inevitable; it was forced. It was imperfect: mistakes were made, including in MI5. But it matters to me today not only to commemorate the victims of 9/11, but to pay sober tribute to all those – from the 457 British service personnel who paid the ultimate price in Afghanistan, to nameless human sources whose courage can never be publicly credited – whose dedication, bravery and ingenuity have made ‘another 9/11’ progressively less likely.
The MI5 I lead in 2026 contends with a threat landscape markedly different to 2001’s. Sadly, mass-casualty terrorist ambition endures, as in the recent conviction of an Islamist extremist who sought automatic weaponry for an assault on Manchester’s Jewish community. But the terrorist threat now sits alongside strategic national security threats posed by capable States. In the aftermath of the Cold War, CIA Director James Woolsey spoke of the West having “slain a large dragon” but facing a “bewildering variety of poisonous snakes”. With a nod to David Kilcullen, we now face the worst of both worlds: dragons are back, but snakes persist.
In responding, MI5 seeks to bring the same unflinching resolve and willingness to adapt that carried us through the traumas of the 9/11 era. Radar built to track interlinked jihadis must now evolve to also detect unknown self-starting would-be attackers. Contending with rising State- backed aggression – whether sabotage subcontracted to criminals, or covert interference in our democracy, or destructive cyber attacks on power stations – demands new laws as well as new tradecraft. All the while driving ourselves hard to stay at the leading edge of tech and AI, which arguably shapes today’s national security frontier more profoundly than does geopolitics.
9/11 highlights the importance not only of out-innovating those who mean us harm, but also of national resilience to cope when, despite heroic efforts, the worst happens. In 2026, unlike 2001, many of the assets, systems and services under threat sit in private sector hands. This means many of the most critical decisions will be taken not in COBR but in boardrooms. We need a new team of teams, preserving an open economy but co-operating across government, industry and academia, to close vulnerabilities and enable swift coherent action when crises hit.
The horrors of 9/11 will never leave me. What sits with me every day, 25 years on, is MI5’s perpetual responsibility to keep adapting, at even greater pace, as we seek to deepen the UK’s resilience - now to both dragons and snakes. We know that the next strategic shock will, by definition, not resemble the last one. That is perhaps the most important lesson of all. We must of course always learn from the last attack – but must beware of preparing brilliantly to fight yesterday’s enemy, using yesterday’s methods, against yesterday’s target. Our adversaries do not offer us that luxury. They adapt because we adapt, and vice versa. The uncomfortable truth is that the next strategic shock may already be taking shape somewhere we are not yet looking.
So we must resist the temptation to admire the defences we built yesterday and instead build the ones we will need tomorrow. This is my call to arms after 25 years: government, business, academia, and the public must treat national security not as the specialist concern of a handful of agencies, but as a shared national endeavour. We cannot wait for the next shock to discover who owns the vulnerability, who has the authority to act, or who was supposed to pick up the phone. We owe the victims of 9/11 – and those who will otherwise become the victims of tomorrow’s attack – something more than remembrance. We owe them preparation, resilience and the courage to adapt before the next shock arrives."
