The novel ends with a bleak portrayal of life in Moscow for defectors who were feted but at the same time suffered the shortages, shoddy furnishings and underwhelming work shared by Soviets.

The novel builds its suspense by focusing on the psychological burdens of the pawns in the game, particularly frustration with the culture of secrecy in the three secret services—British, Soviet and South African—and with the sophisticated amorality of the men at the top.

Greene's characters are complete psychological portraits located within the context of the Cold War and the impact of international affairs on the complicated lives of individuals and vice versa.

In his 1980 autobiography Ways of Escape, Greene wrote that his aim with this book was "to write a novel of espionage free from the conventional violence, which has not, in spite of James Bond, been a feature of the British Secret Service.

He thought that even though the West publicly opposed apartheid, "they simply could not let South Africa succumb to black power and Communism" (from the Introduction to the 1982 edition of The Human Factor).