It is a while since I this film but the title is explained at the start of the film,a voice over and text on the screen says something about a treaty signed by the major powers during the cold war and mentions a secret "fourth protocol" that forbids the planting of small scale nuclear weapons in each others countries. Iiked this film but at the time (1987) many people said that Forysth was a right wing nut,he is but we know know that the USSR had all sorts of crazy ideas about attacking the west because they thought that the west was going to attack them first.
People who liked this fiom should also look out for THE WHILSTLEBLOWER ,another 1980s British spy movie with Michael Caine.
People who liked this fiom should also look out for THE WHILSTLEBLOWER ,another 1980s British spy movie with Michael Caine.