Andrew Parker said MI5 are investigating 500 live cases involving some 3000 people, but terrorists are now planning attacks in days, making it very difficult to defend against them.
British national security is “more under threat than ever” in a “dramatic upshift” in threat levels, with “plots from overseas, plots online, complex scheming and crude stabbings, lengthy planning but also spontaneous attacks,” Parker said.
He added: “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.
“It’s at the highest tempo I have seen in my 34-year career. Complex scheming and also crude stabbings. Lengthy planning but also spontaneous attacks.
“Extremists of all ages, gender and backgrounds united only by the toxic ideology of violent hatred that drives them.”
Parker said MI5 had foiled “20 terror plots in four years”. Twenty major acts have been detected in the past four years and 379 suspects have been arrested in the first six months of this year. He did not comment on the spike in gang violence, up 18 percent and youth killings up 84 percent.
In a major new report, a company Policy Exchange (PE) provided a comprehensive analysis of the struggle against online extremism – the “new Netwar”.
The spate of terrorist attacks in the first half of 2017 confirmed that jihadist radicalisation is a real and present danger to the national security of the UK and its allies.
PS said talk of ISIS’ “decline” in the virtual world has been grossly overstated. The group has shown itself to be adaptable and durable – in spite of the loss of its physical strongholds.
ISIS has been “producing extremist content online at a consistent rate and this is spread across a vast information ecosystem: it is disseminated to core followers via Telegram, before being pumped out into the mainstream social media space (via Twitter, Facebook and other leading platforms)”.
A survey of public opinion conducted by PE showed that two-thirds of Brits believe the leading social media companies are not doing enough to combat online radicalisation. Three-quarters of people want the companies to do more to locate and remove extremist content.
The company suggested that the UK government take a tougher stance on Internet freedom.