While on a business trip, I bought and read the novel "The Spy Who Came In From the Cold" by John Le Carre. This is set in 1950's Berlin, and tells the story of a British spy who gets one last chance at getting revenge on the East German spy master who killed his agents. It is a gripping story filled with twists and turns, and it has some surprisingly deep meditations on ethics and morality in geopolitics.
There is one passage in particular that stuck with me - the British and Soviet/East German spy masters all do terrible things, but the characters say that the British do it in spite of their ideals, while the Soviets are living out the consequences of their ideology. This is a very interesting claim, and it is left to the reader to decide whether the terrible things that happen are justified by the needs of the state. The novel is deeply ambiguous on this point.
I would highly recommend this book - Le Carre is a master, and this novel is brilliantly paced and wonderfully written.