Head of MI5 issues 'call to arms' in rare public intervention

The head of MI5 has issued a "call to arms" for the whole of society to treat national security as a shared challenge.

In a rare public intervention, released to coincide with the 25th anniversary of the 9/11 attacks on the US, Sir Ken McCallum wrote that his officers must confront a "markedly different" threat landscape today than back in 2001.

"Sadly, mass-casualty terrorist ambition endures... but the terrorist threat now sits alongside strategic national security threats posed by capable states," the director general of the Security Service wrote in an article for The Independent newspaper.

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Citing former CIA director James Woolsey, who spoke of the West slaying "a large dragon" after the Cold War, Sir Ken said: "We now face the worst of both worlds: dragons are back, but snakes persist."

The "dragons" are thought to refer to state-based threats from Russia and China, while the "snakes" are the dangers posed by Islamist terrorist groups such as Islamic State and al Qaeda.

Sir Ken wrote: "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."

The MI5 director general explained the importance of the campaigns to hunt down the leaders of al Qaeda in the wake of the devastating attacks against the Twin Towers in New York and the Pentagon.

"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," he wrote.

"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."

However, he cautioned against complacency.

"We must resist the temptation to admire the defences we built yesterday and instead build the ones we will need tomorrow," he said.

Without specifying any hostile country by name, the MI5 boss talked about the escalating threats posed by attacks under the threshold of conventional war.

"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," he wrote.

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"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 continued: "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 cooperating across government, industry and academia, to close vulnerabilities and enable swift coherent action when crises hit."

(c) Sky News 2026: Head of MI5 issues 'call to arms' in rare public intervention