i feel like the fundamental ideological divide they’re using for civil war is that steve is reacting to the winter soldier while tony is reacting to age of ultron
steve is afraid of being controlled, of being forced to take action or inaction even when his own moral code disagrees, or when he’s not given all the information (this ties a lot into bucky’s arc but that’s a whole other post)
tony is afraid of himself, of what he could do or who he could become without something restraining him, of being the merchant of death with no accountability all over again
steve does what he does because he’s certain that what he’s doing is right; tony does what he does because he doesn’t trust himself to make that call anymore