A Must Read: Inside MI5

This year marks the 100th anniversary of the United Kingdom's Security Service, MI5. To mark the occasion, a Manhattan-phone-book-sized (1,032 pages) authorized history of the secret agency was released on Monday and has drawn some rave reviews for its candor and historical insights from the British press.

Stephen Lander, the MI5 director in 2002, asked Christopher Andrew, former chairman of the faculty of history at Cambridge University and chairman of the British intelligence study group, to write "The Defence of The Realm" in 2002 and gave him unprecedented access to the agency's files.

MI5 did conduct a security review of the manuscript, but no restriction was placed on the judgments Andrews made in the book. As a result, Andrews produced a history that "laid bare" some of MI5's most closely held secrets, SkyNews reported in its review titled "MI5 Revealed: 'Spies, Lies And Swear Words.'"

The security service, Andrews disclosed, tried to wake up Prime Minister Neville Chamberlain in the 1930s to the fact that Adolf Hitler referred to Chamberlain using a pejorative that I cannot repeat on a G-rated Web site.

Andrews detailed that MI5 spied on a lot folks, including at least one prime minister, Harold Wilson, and started monitoring his contacts with Soviet and East European diplomats in 1945, the BBC reported.

Lander said that no other major intelligence agency had opened up its files to an independent historian in this way, but now that MI5 has led the way, maybe the CIA would like to follow.

Defence of the Realm, published buy Penguin Books is available in the UK, but is expected to be available in the United States next month.