In early 1951, Liddell notes that evidence has come in suggesting Foreign Office man Donald Maclean may be a Communist spy.

BBC: Cambridge Spies: MI5 diaries revealed

John Philby, father of the infamous Communist spy Kim Philby, converted to Islam in order to serve as a top-level intermediary between then-King Ibn Saud and Standard Oil of California (now ChevronTexaco).

FORBES: The Prize

In recent weeks tens of thousands of South Koreans, alarmed by some lurid reports of communist spy rings active in the South, have taken to the streets to demonstrate in favour of retaining it.

ECONOMIST: The case for vigilance versus the case for greater liberty