From the back cover:

Gordon Thomas, a leading expert on the intelligence community, returns in Secret Wars to provide the definitive history of the famed MI5 and MI6.

Thomas's wide-sweeping history of two of the oldest and most powerful agencies in the world chronicles a century of both triumphs and failures. He recounts the roles that British intelligence played in the Allied victory in World War II; the postwar treachery of Great Britain's own agents; the defection of Soviet agents and the intricate process of 'handling' them; the cooperation between the British and the Americans in the search for Osama bin Laden; and the ways in which MI5 and MI6 have fought biological warfare espionage and space terrorism.

Based on prodigious research and interviews with significant players from inside the British intelligence community , this is a rich and even delicious history packed with intrigue and information only the author could have attained.