“The secret nature of this struggle makes it hard for those not directly involved to understand some of the skirmishes,” he adds. At any one time, MI5 had a “handful” of investigations that involved the “real possibility of a terrorist attack being planned against the UK”, he says. “Most turn out to be the real thing.”
The percentage of “priority” plots linked to al-Qaeda in the tribal areas of Pakistan had dropped from 75 per cent two years ago to 50 per cent now. The threat had increased from Somalia and Yemen.
Mr Evans says a “significant number” of British residents are training in camps run by the al-Qaeda-linked group al-Shabaab. As many as 100 Britons of Pakistani, Bangladeshi and West African backgrounds had travelled to Somalia.
The country “shows many of the characteristics that made Afghanistan so dangerous as a seedbed for terrorism in the period before the fall of the Taliban,” he says. “I am concerned that it is only a matter of time before we see terrorism on our streets inspired by those fighting alongside al-Shabaab.”
The web grows. Be vigilant. (That is vigilant, not vigilante.)