The Little Drummer Girl (1984)

A Palestinian bomber has killed an Israeli diplomat and his family and the Israeli plot to neutralise him becomes convoluted as they select an American Actress (Charlie) to impersonate the Bomber's brother's girlfriend after the Israeli's capture and kill the brother. Charlie is placed into a world where she begins being an actress, then becomes a spy, then is trained by the Palestinians as a guerrilla and finally is sent to deliver a bomb. She is chronically confused by how far she is really supposed to go in her impersonations and how much of herself she must give up. From the book by John Le Carre