It’s a fact that the Impossible Mission Force has consistently had a problem with past members becoming traitors.
Mission: Impossible saw the Phelpses (Jon Voight and Emmanuelle Beart) and disavowed operative Krieger (Jean Reno) almost release the NOC List onto the open market, while its direct sequel, Mission: Impossible 2, literally saw Sean Ambrose (Dougray Scott) defecting mid-mission.
Rounding out the rogue’s gallery pre-Rogue Nation is Mission Impossible 3’s IMF Assistant Director John Musgrave (Billy Crudup) and Ghost Protocol’s Kurt Hendricks (Michael Nyquist), both of whom compromised IMF operations on the behalf of their sinister deeds.