The Manchurian Candidate (1962)

A former Korean War POW is brainwashed by Communists into becoming a political assassin. But another former prisoner may know how to save him.

Director: 

John Frankenheimer

Writers: 

Richard Condon (based on a novel by), George Axelrod (screenplay)

Stars:

 Frank Sinatra, Laurence Harvey and Janet Leigh 

This film is basically about a soldier (Raymond Shaw) who has worn the medal of honour and then the other soldiers (Marco, Melvin) start having nightmares about the war and having suspicions that they were brain washed to think that Shaw saved them all in the war. Marco then starts digging things up about the war. Mean while, Shaw gets controlled when he starts playing solitaire and he can get controlled to do anything, he kills his newly wed wife and her father. Then at an election, his mother makes assigns him to kill a Presidential nominee in his speech, marco tries to persuade shaw to break the links of the brain wash and instead of killing the nominee, he kills his mother and his stepfather and then he kills himself.

 This film was a thriller as well as psychological included. In this film, they had a quite few sequences where the soldiers were seen being brain washed, one bit of the sequence would be at a sort of tea party with ladies and another would be the korean soldiers.