Mole (espionage) - Definition and Overview

A mole is a spy who works for an enemy nation and works within his nation's government. A mole differs from a defector in that a mole is a spy before gaining access to confidential information while a defector only becomes a spy after gaining influence. However, some use the term mole to describe any agent of a foreign power within a government organization.

Perhaps the most famous examples of moles are the Cambridge Five, five men recruited as students at Cambridge University who later rose to high levels in various parts of the British government. Because of the long time of preperation and the difficulty in inserting moles they are quite rare in the top levels of espionage. For instance there was only one mole to ever penetrate the CIA: Karl Koecher. Moles are far more common in police work where they are known as undercover officers.