According to a BBC
Interview with Rimington, there is no exact equivalent to MI5 in
the USA - the nearest equivalent is what used to be called the Foreign
Counter Intelligence arm of the FBI. She goes on to say that "MI5 is a civilian
intelligence service with no powers of arrest or any other police powers, but a
lot of investigative powers. For example, tbey have the power to intercept
communications, follow people around, and search houses and cars. Its job is to help
to protect the country against serious threats to our national security by
generating intelligence, assessing it and taking action on it to prevent the
Rimington's autobiography, Open Secret, was published in 2001 and a new thriller, Secret Asset, will be published this August.
Incidentally, having a female in charge of MI5 wasn't a one-time aberration in the system - as witnessed by the fact that the current DG is Eliza ...