Does Britain have the Secret Service it needs? After the Peter Wright case. the Secret Service is in the spotlight as never before.
David Dimbleby investigates its role in Britain today.
If the Secret Service reveals its secrets, how can it do its job? But if nothing is known of it, how can we trust what it does? Should Parliament have the power to oversee its activities?
What are the views of: the judges who have investigated it; the politicians responsible for it; the people who have worked in it?
From Australia and America, past and present Heads of Intelligence give their opinions.
Director JOHN WILKINSON Producer SARAH NATHAN
Executive producer TIM GARDAM