According to Daniel Ellsberg Lansdale claimed that he was fired by President Kennedy 's Defense Secretary Robert McNamara after he declined Kennedy 's offer to play a role in the overthrow of the Diem regime .
Daniel Ellsberg was at one time a subordinate to Lansdale .
According to Daniel Ellsberg , who was at one time a subordinate to Lansdale , Lansdale claimed that he was fired by President Kennedy 's Defense Secretary Robert McNamara after he declined Kennedy 's offer to play a role in the overthrow of the Diem regime .