There are certain things we all know about Captain America: Civil War. We know the teams, we know the new cast members and mostly who they're playing, and we know it will at least partly be based on the comic book event of the same name. What isn't yet clear is how closely the film will be based on the comic book arc, with a distinct suggestion that it won't be very much at all. Too many of the key details and events are logistically or narratively impossible, and there are some serious gaps that are so far being double-stuffed with theorising and wild speculation. That includes precisely what causes the titular Civil War to kick off in the first place. As it stands, Captain America and Iron Man are still best friends, bantering their way towards the credits in Age Of Ultron, and despite some misgivings, the majority view does seem to be that the damage caused in both New York and Sokovia have been necessary evils to combat even worse possibilities. But soon everything is going to change, as heroes face off against heroes, and long-term friendships are brushed aside because of political allegiances, with the ominous shadow of superhero regulating Accords looming large over everything. So, what exactly is it that causes the Accords to come into existence and all out war between Cap's and Iron Man's teams to escalate?
