Just how big is the terror threat?

The shrieking headlines following Jonathan Evans’s speech show how hard it is for MI5 to make the case for its work

The head of MI5, Jonathan Evans, made his speech to the Worshipful Company of Security Professionals. Photograph: PA”Terror attack risk is doubled,” shrieks the headline on the front page of the Daily Telegraph. “Security services fighting terror on more fronts than ever,” claims the Times on page three. He may not mind the headlines, he may even welcome them, but it’s not what Jonathan Evans, the head of MI5, said.

The security and intelligence agencies make their case like any other lobby. But they have a particular problem. We know what the armed forces and the police are up to because they are either in full view of the public (the police) or fighting and dying for Queen and country (British troops in Afghanistan). MI5 and MI6, however, are involved in intelligence gathering, by definition a covert activity.

Yet from time to time they want to make their case in public, and indeed they should. The trouble is they do it so rarely that when they do, their comments are taken out of all proportion. Hence the headlines, quoted above.

Evans, who on Thursday night was addressing the Worshipful Company of Security Professionals (one of the City’s newest livery companies), said the threat from dissident republican groups in Northern Ireland was growing, something that is manifestly obvious, and that there was a serious potential threat from UK nationals returning from jihadist training and fighting in Somalia, something the spooks have been warning about for some time.

Evans correctly warned that the assumption that terrorism was 100% preventable, which he said had been imported from the US media, was “nonsensical”. Yet he also said that while his agency’s capabilities had improved in recent years, “there remains a serious risk of a lethal attack taking place”. He added: “I see no reason to believe that the position will significantly improve in the immediate future.”

Intelligencegathering and countering terrorism is, crucially, a question of judgment, nuance and managing risk. The security and intelligence agencies are unlikely to minimise the threat, publicly at any rate. Yet exaggerating it can lead to cynicism and the proverbial danger of crying wolf.

There can be no doubt that Evans has briefed David Cameron and Nick Clegg. MI5 will not escape the cuts completely but should be able to cope with the 10% or so the Treasury may demand. Judging by Evans’s speech, the security service is concerned more by the coalition government’s review of the mass of anti-terror legislation introduced under 13 years of Labour. “The government cannot absolve itself of the responsibility to protect its citizens just because the criminal law cannot, in particular circumstances, serve the purposes,” he said, in an apparent reference to control orders.

“The secret nature of this struggle [investigating people suspected of being involved in terrorism] makes it hard for those not directly involved to understand some of the skirmishes that come into the public domain,” he continued. This sounds like special pleading. If it is, the question is: is it, unlike those headlines, justified?