This is a cold war thriller whose primary sin is being boring, which is a death knell to the genre. The plot is basically fine, a standard cold war espionage story, and the acting is fine, standard British fare of the era. There isn’t anything special about it, and I may have been unfortunate to recently review Funeral in Berlin but there’s nothing here that Funeral in Berlin didn’t do better.
Closest comparison: It’s like Face/Off made by the BBC.
Setting: Political Thriller
Plot: Political Thriller
Tone: Drama