Because of renewed tensions between the US and Russia, people talk about a new Cold War, but the current situation is entirely different from the situation which pertained for forty years or so after World War 2, culturally as well as in terms of the geopolitical strategic balance.
The Cold War was clearly a very dangerous time in terms of the risk of a massive nuclear war. But in some other ways maybe it wasn't so bad – compared, that is, to now. It was certainly a more ordered and culturally sophisticated time, quite different from our own.
John le Carré worked for both MI5 and MI6 (i.e. the British Security Service and the Secret Intelligence Service), and his early novels draw heavily on these personal experiences. The tone of the books is dark, but not overwhelmingly so. They depict a shadowy, brutal and morally ambiguous secret world but always against the backdrop of ordinary life, and specifically of the strangely reassuring middle-class world of post-War England and Germany.
A link is provided to an old blog post of mine which was prompted by my reading The Spy Who Came in from the Cold.