Trivia: Peter Graves was asked to reprise his role as Jim Phelps for this movie. When Peter found out that Jim was the main villain for the film, he promptly turned it down.
Trivia: Originally, Alan Silvestri was hired to write the score, but it was eventually decided that his musical style clashed with the tone of the film, and he was replaced by Danny Elfman.
Trivia: Director Brian De Palma reportedly had creative difficulties with Tom Cruise, who was also a producer and thus had final say in the decisions made during production. While this has been disputed, many have noted the fact that De Palma did very little press for the film (including "politely excusing" himself from scheduled media interviews at the last moment) and never took up an offer to record an audio commentary for the film as evidence.
Trivia: The last major Hollywood film to be released on the Betamax video-tape format.
Trivia: An early draft of the script was set to feature several characters from the original series all being killed off to raise the stakes for the new characters. The producers wanted to bring back as many of the original actors as possible. All declined, as they felt it was disrespectful to the original series. As a result, only the character of Jim Phelps was brought back, albeit as a surprise villain and not a hero.
Answer: Ethan never thought it was a mole hunt to trap Jim. He found out from Kittridge at the restaurant that it was a mole hunt, but Kittridge believes that Ethan is the mole (the money his parents mysteriously receive). At the station Ethan realises that Jim must be the mole since it is too convenient both he and his wife survived. However, the hunt to catch the mole was never directed at Jim - Kittridge never suspected him until at the end when he sees Jim alive.
swordfish
Actually had suspicions before Jim showed up. Ethan found the Bible that was stamped from the Drake Hotel. Where Jim had literally just come back from before the mission. It made no sense otherwise why that would be in Jim's possession.