There is something plausible abut Michael Caine's performance here. He ("Preston") is the antithesis of Sir Alec Guinness's "George Smiley" - a hard nosed, blunt spy catcher who hates toeing the line with his bosses. After a bit of clandestine activity, he is on his way out and is sidelined until a seemingly straightforward fatal accident gets his alarm bells ringing. Meantime, KGB agent "Petrofsky" (Pierce Brosnan) arrives in the UK and - eventually - takes up residence near an American Air Force base equipped with nuclear missiles. What's he up to and can "Preston" find out and thwart his…