By now an atmosphere of subdued tension, of hushed, behind-the-hand conversations and clandestine street-corner meetings, is as indigenous to British films as Wellingtons and brollies. If the cinema is any gauge, espionage, double-agenting and secrets trading are to England what baseball is to America -- a national pastime and, for some, an obsession.

This is the thick, dodgy environment of "The Whistle Blower," a new spy thriller starring Michael Caine. At GCHQ Cheltenham, home base of the British intelligence force, the Dodgson case, in which an employe (played by Bill Wallis) was found guilty of spying for the Soviets, has prompted a new spirit of diligence, and paranoia. For Bob (Nigel Havers), a brilliant young linguist specializing in Russian, the aftermath of the Dodgson affair, with employes being questioned regularly about their activities and encouraged to rat on one another, only caps a growing cynicism about the moral distinctions between us and them. For most of his life, he's had his nose in books and hasn't looked up long enough to reflect on the larger implications of his work. But recent events have radicalized him and at 28, he wants to leave the world of cloak-and-dagger snooping. "Underneath our daily lives is an entirely secret world," he says. "And their secret world has put out the light of the ordinary world."

"The Whistle Blower," directed by Simon Langton, is essentially about the lengths to which this covert world will go to protect itself and its secrets. As a thriller in the John Le Carre/Len Deighton manner it's rather routine and sluggish. Langton, who in 1982 shot "Smiley's People" for the BBC, should feel at home in this densely shrouded milieu, but he's unable to give the secret world that Bob speaks of any substance or reality. (As a spy piece, "Smiley's People" seemed unnecessarily drab and stolid, too.)

The British, represented here by James Fox and Gordon Jackson, have to be concerned about internal security and potential double agents because if they're not, their partners, the Americans, will no longer allow them access to their "giant spy machine," leaving them at the mercy of the Soviets. In their attempts to satisfy the Americans that they are on top of the situation, they set about following the various trails running from Dodgson himself, one of which, in its circuitous way, leads to Bob.

Up to a point, this spy versus spy maze is intelligently, if not thrillingly, laid out. Langton can't seem to tighten the screws when they need to be tightened. And the events don't seem to have any cumulative effect; nothing builds, as it must in a film of this sort.

Langton's greater talents seem to lie in bringing out the more human elements in Julian Bond's script. He's very good, for example, at establishing the relationship between Bob and his father Frank (Michael Caine). Bob's disaffection is a puzzle to his father, and as a former naval officer who tossed away his commission by impetuously taking a poke at a superior, he's grown cautious with age and is not particularly sympathetic to his son's need to cut out and build a new life.

In addition, Frank can't bring himself to believe in Bob's conspiracy theories, though in the end his instincts prove him wrong. On one level, the movie is about Frank's coming to knowledge about queen and country -- it's the story of his radicalization as much as it is Bob's.

As he has gotten older, Michael Caine's looks have left him; he's no longer the street-brash, cheeky playboy of "Alfie." But something softer and more vulnerable -- something deeper -- has been gained. As a result, Caine has become one of the screen's most eminently readable actors. There's nothing cloaked or calculated in his style. He's there, effortlessly.

As Frank, Caine has a handful of terrific moments -- like the one in which he gets an old war buddy (Barry Foster), who's also, as it turns out, a CIA setup man, liquored up in order to pump him for information about his son -- but ultimately, his performance cannot transcend the material. As it goes along, the movie gets increasingly blockheaded. A confrontation between Frank and Sir Adrian Chapple (Sir John Gielgud), the high-ranking civil servant at the center of the conspiracy, is clumsily staged and virtually pointless. (This is not one of Gielgud's better cameos.) And the resolution to the drama is, to say the least, an anticlimax. In fact, it's no climax at all. The movie just dribbles to finale, feebly, like so much rainwater into the Thames. The Whistle Blower, at the Outer Circle, is rated PG and contains no offensive material.