The suicide bombers who struck London on 7 July 2005 killed 52 innocent people and wounded hundreds more. All of them must live with their memories. And the rest of us will always remember where we were when we heard that London had been hit by the worst terrorist attack in its history.

Women tend to break the network of friends they make, but it is a habit that men have learned. It is an approach to life that involves planning almost without thinking about it. And men sustain this. I came from a northern grammar school. I had a good education, but I didn't have a good network.

Well, one thing's very clear, that terrorism isn't just a threat which is external to Western countries. It's not simply a foreign menace that comes from overseas to strike our cities. It can and it does, as we now know, come from within our own countries and from inside our own populations.

One of the marked characteristics of the U.K. security industry as compared with defence is the lack of company scale. This can put our firms at a competitive disadvantage when it comes to big contracts.

The British security industry has the capacity to be a world leader and it should be our shared objective to achieve this.

I am sorry to be leaving the BBC. I have enjoyed a fascinating seven years at the corporation and am particularly proud to have played a small part in the development of the BBC's Global News services, BBC World Service and BBC World.

The Internet plays an ever more significant role in the sedulous promotion of terrorism. We know that in the U.K., groups gather to view the preaching of violent men located many thousands of miles away and that this does have a powerful effect on young minds.