The Fourth Protocol (1987)

Director: John Mackenzie
Cast: Ian Richardson, Joanna Cassidy, Julian Glover, Michael Caine, Michael Gough, Ned Beatty, Pierce Brosnan, Ray McAnally

Synopsis:

Led by Kim Philby, Plan Aurora is a plan that breaches the top-secret Fourth Protocol and turns the fears that shaped it into a living nightmare. A crack Soviet agent, placed under cover in a quiet English country town, begins to assemble a nuclear bomb, whilst an MI5 agent attempts to prevent its detonation.