The Marvel Cinematic Universe has successfully taken the continuity and character crossovers that people love in comic books and transplanted it into film. They have also taken several of their successful major comic storylines and rewritten them for the screen. There is one thing that the new trailer for Captain America: Civil War has made clear, however, and that is that the movie version of this storyline will have a very different perspective than the comics.
The thing about these major events in comic books is that they take place across all of the books. If you read the Captain America comic, you see what he’s doing, while the Iron Man comic book will give you his perspective on the same information. Each Marvel movie focuses on a different character. Only the two Avengers films have given us multiple points of view in the same movie. While Civil War has the feel of an Avengers film, because all of the same characters are in it, it is most certainly not an Avengers story. This will be a Captain America movie, and all that we see will be through his eyes.
All the scenes of Tony Stark or Iron Man, or any other hero for that matter, that we see in the trailer are when they are interacting directly with Steve Rogers. Since this is a Captain America movie, that may not be too surprising, but it means we’ll likely only get one point of view on the conflict. The thing about the Civil War of the comics is that there wasn’t necessarily a "bad guy" at all. There were two sides who both wanted to do the "right" thing, they just had very different ideas about what that was. This version is very likely to paint the Iron Man side as a much more clear "enemy" because that’s how Cap will view them. There will certainly be some nuance to be sure, there are more Avengers movies to come after all and we fully expect Captain America and Iron Man to stand together again at some point, but Cap tends to see things in black and white so if Iron Man is in the way, he’ll be the enemy.
Civil War could have certainly been a straight up Avengers movie, so the fact that it isn’t is certainly intentional. It’s obviously a deliberate decision to focus on Cap’s side of the struggle, though exactly why is not entirely clear. It could just be a simple way to ratchet up the tension for the upcoming films. By making Tony Stark’s side more enemy than opposition, it will likely make things look bleaker as we begin to move toward The Infinity War, which will in turn make the payoff of the return of the Avengers all the more satisfying. It could also be because Marvel’s not going to be able to afford to keep Robert Downey Jr. around much longer, and this is the beginning of writing him off.
