I could not help but fanedit the whole movie in my mind while watching, but mostly to trim redundant sequences and the atrocious (signature Nolan) expository dialogue.
As for chronology I think the movie is actually pretty linear. The thing to grasp is that its all a closed loop: all that happens to the Past Protagonist is happening simultaneously to the Future Protagonist, but of course, in reverse. Is just that we’re stuck with the past perspective for the sake of catharsis.
In the first opera scene, the Future Protagonist is glimpsed being there to test the Past Protagonist, so that he can recruit himself into Tenet - and the whole film follows this thread until Tenet secures the Algorithm. That’s the turning point between Past and Future, where the Past Protagonist becomes aware of his role and as now Future Protagonist, commits to do the whole chain of events, starting with organizing Tenet up until he first recruits himself back into the Opera House. The chain of events for the Future Protagonist, that way, would be the reverse order of the movie. That’s the SATOR square coming full circle.
For a fanedit I would say:
- The Opera mission is deliberately confusing to set up the rest of the movie, and even with some mild trimming it could be more straightforward;
- The scientist briefing and the shooting range just make it all worse and add that “to avoid WW3” red herring, so I would completely ditch it. It might feel important to explain the film’s premise but the exchanges with Priya later do a much better job at it;
- The Mumbai break-in is also disposable, as introducing Neil and Priya could easily do without the action and it would save lots of the film’s pace in the first act;
- 50% of Sator and his wife could be gone too, ugh. Specially the boating “accident” and the following drama. I’d say Protagonist blackmails Kat, Kat introduces Protagonist at dinner (no affair implied), Protagonist does business with Sator and moving on;
- The battle royale at the final act is eye-popping but is too over indulgent. The whole operation is kinda nonsensical anyways, and it gets too ridiculous if you stop to think about it. Could be trimmed to give more focus to the main characters who are actually recovering the algorithm and not blowing up city ruins for some reason;
- Lastly, the confrontation between Kat and Sator. Takes waaay too long, but that might be because the warzone sequence just keeps dragging on.
In the end, I think Tenet would benefit greatly with just a reduced runtime and an even pace. Maybe still confusing, but an improved watch of an otherwise entertaining cinema experience.