Sleeper agent

In espionage, a sleeper agent is one who has infiltrated into the target country and has "gone to sleep", sometimes for many years. The agent does nothing to communicate with the sponsor or any existing agents or to obtain information beyond what is in public sources. The agent can also be referred to as a 'deep cover' agent. The agent acquires jobs and identities, ideally ones that will prove useful in the future, and attempts to blend into everyday life as a normal citizen. Counter-espionage agencies in the target country cannot, in practice, closely watch all those who may possibly have been recruited some time before.

In a sense, the best sleeper agents are those who do not need to be paid by the sponsor, as they are able to earn enough money to finance themselves, averting any possibly traceable payments from abroad. In such cases, it is possible for the sleeper agent to be successful enough to become what is sometimes termed an "agent of influence".

Sleeper agents who have been discovered have often been natives of the target country who moved elsewhere in early life and were co-opted (perhaps for ideological or ethnic reasons) before returning to the target country. That is valuable to the sponsor as the sleeper's language and other skills can be those of a native and thus less likely to trigger domestic suspicion.

Choosing and inserting sleeper agents has often been difficult, as it is uncertain that the target will be appropriate some years in the future. If the sponsor government and its policies change after the sleeper has been inserted, the sleeper may be found to have been planted in the wrong target.

In fictional portrayals, sleeper agents are sometimes unaware that they are sleepers. They are brainwashed, hypnotized, or otherwise conditioned to be unaware of their secret mission until activated. Examples of such stories are:

• The Manchurian Candidate (the novel and its film adaptations), in which some Americans are captured by Soviet intelligence forces, given post-hypnotic commands, and returned to their lives in the U.S.
• The 1977 film Telefon, in which Russian agents believe they are ordinary Americans until their memories are unlocked with a special activation phrase
• The 2010 film Salt, in which an accused sleeper agent goes on the run to try to clear her name only to discover she actually is a sleeper
• The 2012 film Thuppakki, in which the sleeper cells attack the Mumbai city.
• The 2014 film Captain America: The Winter Soldier, in which Bucky Barnes has been brainwashed after World War II
• The 2015 film American Ultra, in which the Small-town stoner Mike Howell spends most of his time getting high and writing graphic novels. What Mike doesn't know is that he was trained by the CIA to be a lethal killing machine. When the agency targets him for termination, his former handler activates his latent skills, turning the mild-mannered slacker into a deadly weapon.
• The 2010 video game Call of Duty: Black Ops, in which the protagonist, CIA Operative Alex Mason is captured during the Bay of Pigs Invasion and is gifted into Soviet captivity, where he is brainwashed into a sleeper agent.

• Double agent
• Mole (espionage)
• Resident spy
• Clandestine cell system
• Silent majority