There’s no question that Captain America: The First Avenger ends with Cap frozen in ice, beginning his journey to the modern age (and The Avengers). But does that mean the semi-inevitable Captain America 2 must be set in the modern day? Apparently that’s still up in the air.
Screenwriter Christopher Markus tells MTV: “t’s sort of a weirdly huge opportunity for storytelling in that you know modern Cap through the Avengers at that point, and… there’s going to be a lot of his World War II history we haven’t shown. We’re going to have two entire timelines to play with.”
What I could see happening would be storytelling in the mold of Ed Brubaker’s run on the comic. Brubaker has often used elements of Cap’s WWII history to complement, comment on or inform the current adventures, and many of Brubaker’s stories have major WWII components. It’s a good way to have your cake and be in WWII. Cap could be dealing with the return of an old enemy in the modern day (or the offspring, continuation of, etc) and the film could structure the story like The Godfather Part II. Which is probably a very reasonable thing to say about a superhero sequel.