Picture dated April 30, 1970 shows republican president Richard Nixon gesturing during a press conference announcing the entry of American soldiers in Cambodia. Despite pleges to protect South Vietnam, former US president Richard Nixon privately vowed to "cut off the head" of its leader unless he backed peace with the communist North, tapes released on June 23, 2009 showed. Getty Images logo Getty Images 7 months ago

Picture dated April 30, 1970 shows republican president Richard Nixon gesturing during a press conference announcing the entry of American soldiers in Cambodia. Despite pleges to protect South Vietnam, former US president Richard Nixon privately vowed to "cut off the head" of its leader unless he backed peace with the communist North, tapes released on June 23, 2009 showed.