Is UK safer now than before 9/11 terror attacks?
7 September 2011 Last updated at 20:13 BST
It is nearly a decade to the day since the shocking images of the 9-11 terror attacks were beamed around the world.
In Britain, the 10 years that followed have seen the London underground atrocities and a huge shake-up of counter-terrorist policing, intelligence and community relations.
Frank Gardner has been assessing whether we are any safer now than we were then.