"Tinker, Tailor, Soldier, Spy", by John le Carre

[From an Amazon review]:

"Tinker, Tailor, Soldier, Spy" has been called the best espionage novel ever written. John Le Carre's cynical and spellbinding spy thrillers are so unique because they are based on a wide knowledge of international espionage. Le Carre, (pen name for David John Moore Cornwell), acquired this knowledge firsthand during his years as an operations agent for the British M15. Kim Philby, the infamous mole, actually gave Le Carre's name to the Soviets long before he defected. The author's professional experience and his tremendous talent as a master storyteller and superb writer make this book one of the best novels I have read in the genre.

"Tinker, Tailor..." is the first in what has come to be called LeCarré's "Karla (or Smiley) Trilogy", in which English spy George Smiley is pitted against the Soviet spymaster Karla. Written during the Cold War, it is a portrait of that time, with its paranoid and morally ambiguous view of global politics.