MI5 comes clean
London - The first official history of Britain's MI5 was published on Monday, ending 100 years of secrecy over British spying during two world wars, the Cold War and the current fight against Islamic extremism.
The Defence of the Realm was written by Cambridge University historian Christopher Andrew, who was given virtually unrestricted access to some 400 000 files - and even joined the domestic intelligence agency himself.
The book's revelations include how MI5 officers told then Prime Minister Neville Chamberlain in 1938 that Hitler privately called him an "arsehole", after he appeased the Nazi regime over its annexation of the Sudetenland.
It also features previously unseen surveillance pictures of Soviet agents, Irish Republican Army (IRA) operatives and Islamic extremists plotting and shopping for bomb parts.
Andrew said he had been "pretty thrilled and a bit nervous" to write the more than 1 000-page book. "Every other day, I would say: 'Oh crikey, I never knew that'," he told reporters.
First for intelligence
Stephen Lander, the former head of MI5 who commissioned the book in 2002 to mark its centenary this year, said MI5 was the first Western intelligence agency to undertake such a project.
One of the main triggers for the book was the September 11 2001 attacks in the United States and the advent of al-Qaeda-type suicide attacks, which meant that security services needed much more public support.
"It is quite clear within the service that our world has changed fundamentally. The suicide bomber is a different order of threat to the IRA," he said.
"Maybe we didn't appreciate at that stage the extent to which that change was going to affect us post the invasion of Iraq," he added.
"But we certainly did see that we would need to gear up to a new sort of approach and a new sort of work and we would particularly need the support of the public."
The book is the latest step taken by MI5 in recent years to make its operations more open, while never compromising the confidentiality essential to much of its work.
Before the appointment of Stella Rimington in 1992, its chiefs were never officially named or photographed, and publication of her identity caused a news frenzy.
By contrast, earlier this year, current head Jonathan Evans gave the first-ever newspaper interview by someone in the job.
Recruitment has also changed.
In previous years, potential spies were often approached surreptitiously through colleges at Cambridge and Oxford universities.
But now MI5 runs advertisements and has a careers section on its website, launched in 2002, which stresses its interest in female and ethnic minority recruits.
A sizeable chunk of the book is devoted to MI5 during the Cold War, including the Cambridge Five spy ring which Andrew describes as "the ablest group of British agents ever recruited by a foreign power."
He said Britain had significant problems coping with Soviet agents until 1971, when it expelled them en masse.
"Up to 1971, we couldn't really deal with them," he said. "There were just too many of them - in other words, they outnumbered the capacity of the security service.
In the last two decades of the Cold War, the service's focus switched from counter-espionage to counter-terrorism, particularly the IRA and in the Middle East, Andrew added.