Trivia: At one point in time, this was going to be the final entry in the series to star Tom Cruise. As originally intended, Cruise (Ethan Hunt) would have retired from field work at the end of the film and become the new head of IMF, while Jeremy Renner would become the new series lead. This was reportedly in part due to several infamous incidents involving Cruise in the mid-2000's, including his notorious Oprah Winfrey interview. These events caused issues during the promotion of "Mission: Impossible III," and the studio was still nervous about them years later. Eventually, cooler heads prevailed, and Cruise was thankfully allowed to stay with the series.
Trivia: The language spoken in the video by Kurt Hendricks (in the IMF section of the train) is not Russian, despite the eagle and nametags in Russian, but Swedish, Mikael Nyqvist's (the actor portraying Kurt Hendricks) native language.
Trivia: The number A113 (which appeared in Brad Bird's previous films The Incredibles and Ratatouille) makes two appearances here. The first is on the side of Hanaway's ring in the flashback sequence, and the second is verbally as Ethan's agent ID that he recites through the phone after he escapes from the hospital. (00:14:40)
Trivia: SPOILERS In the original script, Julia was supposed to have genuinely been killed off between films. The reveal of her survival was only added when the film was halfway through shooting.
Trivia: When Ethan escapes from a Russian prison at the beginning of the film, he gets his latest mission from a payphone. The code Ethan uses to access the message - 07362 - are the digits of Tom Cruise's birthday - July 3, 1962.
Trivia: The first live-action feature film directed by Brad Bird. Bird is mostly known for his work on animated feature films. He directed both of the "Incredibles" films, the cult-classic "The Iron Giant" and "Ratatouille."
Answer: He considers Hunt to be a friend, so did what he asked. In addition, by carrying out the deal he has ingratiated himself with Sidorov as well.