5 Nov 07 address to the Society of Editors by the Director General of the Security Service, Jonathan Evans:

Intelligence, Counterterrorism and Trust
....You may recall that in her speech this time last year, my predecessor, Eliza Manningham-Buller, pointed out that this country was facing an increasing threat from Al Qaida-inspired terrorism. When she spoke, MI5 had identified around 1,600 individuals who we believed posed a direct threat to national security and public safety, because of their support for terrorism. That figure today would be at least 2,000. This growth, which has driven the increasingly strong and coordinated government response, is partly because our coverage of the extremist networks is now more thorough. But it is also because there remains a steady flow of new recruits to the extremist cause.

And it is important that we recognise an uncomfortable truth: terrorist attacks we have seen against the UK are not simply random plots by disparate and fragmented groups. The majority of these attacks, successful or otherwise, have taken place because Al Qaida has a clear determination to mount terrorist attacks against the United Kingdom. This remains the case today, and there is no sign of it reducing. So although MI5 and the police are investigating plots, and thwarting them, on a continuing basis, we do not view them in isolation. Al Qaida is conducting a deliberate campaign against us. It is the expression of a hostility towards the UK which existed long before September 11, 2001. It is evident in the wills and letters left behind by actual and would-be bombers. And it regularly forms part of Al Qaida's broadcast messages.

This campaign is dynamic, and since my predecessor spoke last year, we have seen it evolve even further.

As a country, we are rightly concerned to protect children from exploitation in other areas. We need to do the same in relation to violent extremism. As I speak, terrorists are methodically and intentionally targeting young people and children in this country. They are radicalising, indoctrinating and grooming young, vulnerable people to carry out acts of terrorism. This year, we have seen individuals as young as 15 and 16 implicated in terrorist-related activity.....