Speech by the Director of the Security Service, Dame Eliza Manningham-Buller, at Queen Mary's College, 9 November 2006:

... I speak not as a politician, nor as a pundit, but as someone who has been an intelligence professional for 32 years...

We now know that the first Al-Qaida-related plot against the UK was the one we discovered and disrupted in November 2000 in Birmingham. A British citizen is currently serving a long prison sentence for plotting to detonate a large bomb in the UK. Let there be no doubt about this: the international terrorist threat to this country is not new. It began before Iraq, before Afghanistan, and before 9/11.

In the years after 9/11, with atrocities taking place in Madrid, Casablanca, Bali, Istanbul and elsewhere, terrorists plotted to mount a string of attacks in the UK, but were disrupted...

Last month the Lord Chancellor said that there were a total of 99 defendants awaiting trial in 34 cases. Of course the presumption of innocence applies and the law dictates that nothing must be said or done which might prejudice the right of a defendant to receive a fair trial...

What I can say is that today, my officers and the police are working to contend with some 200 groupings or networks, totalling over 1600 identified individuals (and there will be many we don't know) who are actively engaged in plotting, or facilitating, terrorist acts here and overseas. The extremists are motivated by a sense of grievance and injustice driven by their interpretation of the history between the West and the Muslim world. This view is shared, in some degree, by a far wider constituency. If the opinion polls conducted in the UK since July 2005 are only broadly accurate, over 100,000 of our citizens consider that the July 2005 attacks in London were justified.

What we see at the extreme end of the spectrum are resilient networks, some directed from Al-Qaida in Pakistan, some more loosely inspired by it, planning attacks including mass casualty suicide attacks in the UK. Today we see the use of home-made improvised explosive devices; tomorrow's threat may include the use of chemicals, bacteriological agents, radioactive materials and even nuclear technology. More and more people are moving from passive sympathy towards active terrorism through being radicalised or indoctrinated by friends, families, in organised training events here and overseas, by images on television, through chat rooms and websites on the Internet.

The propaganda machine is sophisticated and Al-Qaida itself says that 50% of its war is conducted through the media. In Iraq, attacks are regularly videoed and the footage downloaded onto the Internet within 30 minutes. Virtual media teams then edit the result, translate it into English and many other languages, and package it for a worldwide audience. And, chillingly, we see the results here. Young teenagers being groomed to be suicide bombers.

We are aware of numerous plots to kill people and to damage our economy. What do I mean by numerous? Five? Ten? No, nearer thirty - that we know of. These plots often have links back to Al-Qaida in Pakistan and through those links Al-Qaida gives guidance and training to its largely British foot soldiers here on an extensive and growing scale. And it is not just the UK of course. Other countries also face a new terrorist threat: from Spain to France to Canada and Germany...

But just consider this. A terrorist spectacular would cost potentially thousands of lives and do major damage to the world economy. Imagine if a plot to bring down several passenger aircraft succeeded. Thousands dead, major economic damage, disruption across the globe. And Al-Qaida is an organisation without restraint.

There has been much speculation about what motivates young men and women to carry out acts of terrorism in the UK. My Service needs to understand the motivations behind terrorism to succeed in countering it, as far as that is possible. Al-Qaida has developed an ideology which claims that Islam is under attack, and needs to be defended.

This is a powerful narrative that weaves together conflicts from across the globe, presenting the West's response to varied and complex issues, from long-standing disputes such as Israel/Palestine and Kashmir to more recent events as evidence of an across-the-board determination to undermine and humiliate Islam worldwide. Afghanistan, the Balkans, Chechnya, Iraq, Israel/Palestine, Kashmir and Lebanon are regularly cited by those who advocate terrorist violence as illustrating what they allege is Western hostility to Islam.

The video wills of British suicide bombers make it clear that they are motivated by perceived worldwide and long-standing injustices against Muslims; an extreme and minority interpretation of Islam promoted by some preachers and people of influence; and their interpretation as anti-Muslim of UK foreign policy, in particular the UK's involvement in Iraq and Afghanistan.

Killing oneself and others in response is an attractive option for some citizens of this country and others around the world...

As I said earlier, I have been an intelligence officer for some 32 years. And I want again to describe what intelligence is and is not. I wish life were like 'Spooks', where everything is (a) knowable, and (b) soluble by six people. But those whose plans we wish to detect in advance are determined to conceal from us what they intend to do. And every day they learn. From the mistakes of others. From what they discover of our capabilities from evidence presented in court, and from leaks to the media.

Moreover, intelligence is usually bitty and needs piecing together, assessing, judging. It takes objectivity, integrity and a sceptical eye to make good use of intelligence: even the best of it never tells the whole story. On the basis of such incomplete information, my Service and the police make decisions on when and how to take action, to protect public safety...

We are faced by acute and very difficult choices of prioritisation. We cannot focus on everything so we have to decide on a daily basis with the police and others where to focus our energies, whom to follow, whose telephone lines need listening to, which seized media needs to go to the top of the analytic pile. Because of the sheer scale of what we face (80% increase in casework since January), the task is daunting. We won't always make the right choices. And we recognise we shall have scarce sympathy if we are unable to prevent one of our targets committing an atrocity...

As I speak, my staff, roughly 2,800 of them, (an increase of almost 50% since 9/11, 25% under 30, over 6% from ethnic minorities, with 52 languages, with links to well over 100 services worldwide), are working very hard, at some cost to their private lives and in some cases their safety, to do their utmost to collect the intelligence we need.

The first challenge is to find those who would cause us harm, among the 60 million or so people who live here and the hundreds of thousands who visit each year. That is no easy task, particularly given the scale and speed of radicalisation and the age of some being radicalised.

The next stage is to decide what action to take in response to that intelligence. Who are merely talking big, and who have real ambitions? Who have genuine aspirations to commit terrorism, but lack the know-how or materials? Who are the skilled and trained ones, who the amateurs? Where should we and the police focus our finite resources? ...

On July 8 last year I spoke to all my staff. I said that what we feared would happen had finally happened. I reminded them that we had warned that it was a matter of when, not if, and that they were trained to respond - indeed many had been up all night, from the intelligence staff to the catering staff. I told them that we had received many messages of support from around the world, and that we, along with our colleagues in the police and emergency services, were in the privileged position of being able to make a difference. And we did. And we have done so since.

My Service is growing very rapidly. By 2008 it will be twice the size it was at 9/11. We know much more than we did then. We have developed new techniques, new sources, new relationships. We understand much better the scale and nature of what we are tackling but much is still obscure and radicalisation continues. Moreover, even with such rapid growth, we shall not be able to investigate nearly enough of the problem, so the prioritisation I mentioned earlier will remain essential but risky. And new intelligence officers need to be trained. That takes time as does the acquisition of experience, the experience that helps one with those difficult choices and tough judgements...

That brings me on to my final point. None of this can be tackled by my Service alone. Others have to address the causes, counter the radicalisation, assist in the rehabilitation of those affected, and work to protect our way of life...

Safety for us all means working together to protect those we care about, being alert to the danger without over-reacting, and reporting concerns. We need to be alert to attempts to radicalise and indoctrinate our youth and to seek to counter it. Radicalising elements within communities are trying to exploit grievances for terrorist purposes; it is the youth who are being actively targeted, groomed, radicalised and set on a path that frighteningly quickly could end in their involvement in mass murder of their fellow UK citizens, or their early death in a suicide attack or on a foreign battlefield...