From a Wall Street Journal review by Edward Kosner of the book by Benjamin Cunningham titled “The Liar: How a Double Agent in the CIA Became the Cold War’s Last Honest Man”:

John le Carré’s marvelous novels—“Tinker, Tailor, Soldier, Spy” and the rest—evoke a secret world of Cold War espionage with wily spymasters, intrepid and exhausted operatives, squalid betrayals and moral ambiguities. But there was another, real nest of spies in those days in the captive nations of the Soviet Union’s febrile Eastern European empire. Bureaucratic and often inept, these low-rent spooks and their handlers, vassals of Moscow, spied on one another as much as on their adversaries in the West.