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.

We owe it to the victims of the suicide bombers who struck London on 7 July 2005 to find out how the attacks happened and to learn the lessons that will spare lives in the future.

As the BBC approaches the final phase of decisions about its future, it will be important for those involved to be established in post and ready to take responsibility for implementation of the outcome.

The BBC's television, radio and online services remain an important part of British culture and the fact the BBC continues to thrive amongst audiences at home and abroad is testament to a professional and dedicated management team who are committed to providing a quality public service.