Terror attacks will happen in a free society says MI5 chief

Terror attacks cannot be completely prevented in a free society, the head of MI5 has said, as he warned plots were now harder to spot and being hatched in just days.

Andrew Parker said the country was now facing an intense threat from violent Islamist extremists who were devising plots at a tempo he had not seen before in his 34-year-career.

The director general of the Security Service made a rare public appearance to outline the severity of the threat after four jihadist attacks that have killed 36 people since March.

A dramatic increase in the menace this year had seen attackers hatch plots in a matter of only days, he said.

Mr Parker also warned that internet firms were inadvertently helping terrorists conspire and they now had an ethical responsibility to help stop these worst excesses of criminal behaviour.

He called on tech firms to help the government tackle the “dark edges” of the online revolution, which was giving an advantage to violent extremists and enemy spies.

Mr Parker said the “dramatic upshift” in Islamist threats in 2017 meant there “is more terrorist activity coming at us more quickly and it can be harder to detect”.

Speaking in central London, he said MI5 and the police had stopped 20 plots in the past four years, including seven since March, and would “continue to find and stop most attacks”.

But he warned they could not be expected to stop them all and it was likely more would follow.

He said: “Attacks will occur sometimes because this is a free society, a liberal democracy, and we do not monitor everybody all the time and I wouldn't wish to live in a country that was like that.”

He went on: “I think we have to be careful that we don’t find ourselves being held to some sort of perfect standard of 100 per cent, because that just isn’t achievable.”

Mr Parker also said technology firms were inadvertently helping terrorists.

Firms such as Google and Whatsapp have come under accusations from ministers this year of doing too little to take down extremist content or for allowing terrorists a “safe space” to conspire using encrypted messages.

He said: “We all rely on a myriad of brilliant technological advances in everyday life, but an unintended side effect is that these advances also aid the terrorists.”

The ease of online buying, the propaganda potential of social media and the ability to send encrypted messages were all problems, Mr Parker said.

He said: “Addressing these challenges is about partnerships and ethical responsibility. No company wants to provide terrorists with explosive precursors. Social media platforms don’t want to host bomb-making videos. And communications providers do not want to provide the means for terrorists’ planning beyond the sight of MI5.”

He went on: “I believe that there is a responsibility on the companies that offer those services to help governments be able to stop the worst excesses of human criminal behaviour.”

Mr Parker said plots were being hatched both in the UK and overseas and ranged from complex, lengthy conspiracies to almost spontaneous acts of violence.

He said: “These threats are sometimes now coming at us more quickly, whether crude but lethal attack methods - for example using a knife or a vehicle - or more sophisticated plots when in today’s world terrorists can learn all that they need online to make explosives and build a bomb.

“Attacks can sometimes accelerate from inception through planning to action in just a handful of days. This pace, together with the way extremists can exploit safe spaces online can make threats harder to detect and give us a smaller window to intervene.”

Older security threats still remained, he said, with MI5 officers still working on Northern Ireland and counter espionage duties.

He said: “We continue to bear down on terrorism in Northern Ireland with our police partners, and to work against espionage and other clandestine activity by Russia and other foreign states who seek to do Britain harm.”