Thenovelizationof the 1996 film also reveals a bit more about the character’s backstory.
Flashbacks of an incident involving these figures are shown throughout the film, but they are vague and unclear.
The film also heavily implies that Ethan Hunt was a highly skilled criminal.
Ethan has a sense of moral righteousness, a quality not typically associated with criminals.
All that is really known is that she was of great importance to him.
I was never really interested in creating a typical love interest for Ethan.
Once that relationship consummates, that relationship is over."
Ethan could have been in training for a few years before his mission in the first film.