To Catch a Spy: The Art of Counterintelligence
James Olson, Georgetown University Press, £22.50
Counter-intelligence officers are the poor relations of the spy world. Their colleagues in mainstream espionage go out in the field to steal secrets and delight their bosses. The spy-catchers get in the way.
Their job is to ask awkward questions – how can we be sure that this new source is trustworthy? – and to set and enforce annoying rules. Recruits must be screened, a process that is slow and intrusive. Experience and success do not mean you escape scrutiny, including by polygraph, or lie detector, which in the American system plays a big role. Information must be properly compartmentalized, which slows things down.