But now more than ever, I believe this movie is going to suck. Read this article.
"The costume is a flag, but the way we're getting around that is we have Steve Rogers forced into the USO circuit. After he's made into this super-soldier, they decide they can't send him into combat and risk him getting killed. He's the only one and they can't make more. So they say, 'You're going to be in this USO show' and they give him a flag suit. He can't wait to get out of it."
That's a whole new concept and it's one that sounds pretty promising. "It was never in the comics," Johnston said, "because they didn't really need it. In comics, he puts on the costume and the reader just justifies because of the nature of the medium."
How about "he wears a flag cuz he's a fucking United States super soldier and they want the krauts to know who made the ubermensch that just killed the shit out of their front line?" Seriously. This is World War II. You don't need some cutesy subplot about him working at the USO to excuse his costume. Just send him into action!