UK's MI5 chief: Next 9/11 might be taking shape where we are not looking

LONDON- Intelligence services must not dwell too much on past threats but accept that a new strategic shock along the lines of the 9/11 attacks could already be in preparation where they are not looking, the head of Britain's MI5 spy agency said.

In an opinion piece published on Friday to mark 25 years since al Qaeda militants crashed hijacked passenger jets into the World Trade Center in New York and the Pentagon, MI5's Director General Ken McCallum said security agencies had to be ready to adapt to current and future challenges.

"We know that the next strategic shock will, by definition, not resemble the last one. That is perhaps the most important lesson of all," McCallum wrote in the commentary for the Independent newspaper.

"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 ... The uncomfortable truth is that the next strategic shock may already be taking shape somewhere we are not yet looking."

Al Qaeda, though diminished, remains a threat, as does the aspiration of that group and other militants for mass casualty attacks, McCallum said.

This was recently borne out by a foiled Islamist plot to kill hundreds in gun attacks on the Jewish community in the northern English city of Manchester, he added.

But McCallum said MI5 was also facing rising state-backed aggression, ranging from sabotage carried out by criminal proxies to cyberattacks on power stations.

Unlike in 2001, many systems and services are in the hands of the private sector and it will require governments, businesses and academia all working together to close vulnerabilities and to respond swiftly in a crisis, he said.

"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," he wrote.

"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."

Reporting by Michael Holden; Editing by Gareth Jones/Reuters