A Not-So-Secret Service

"It is of the essence of a secret service that it must be secret, and if you once begin disclosure, it is perfectly obvious . . . that there is no longer any secret service." That wisdom, intoned by Sir Austen Chamberlain during his tenure as Foreign Secretary from 1924 to 1929, has long been the motto of British governments. Indeed, officials traditionally denied the very existence of a secret service.

No longer. Peter Wright, a disgruntled former deputy director of MI5, Britain's counterintelligence agency, has angered officials as high as Prime Minister Margaret Thatcher by planning to publish a book...