I'm not sure this would qualify as a "remake".
A movie about Iwo Jima based on historical fact. And with out some fictional crap thrown in to enhance an already moving event like was done in Saving Private Ryan. There were way, way too many authentic stories associated with the Normandy landings to have to create one for the sake of a script.
A good deal of the script could come from the book, Flags Of Our Fathers, by James Bradley, but would not have the flag raisers as the center of attention. I am afraid the movie would be quite long in order to get the viewer emotionally attached to the main characters lives before, during, and after the battle. The pre-invasion strategies and rehearsals, the defender's preparations and mind set.
BTW, if you have not yet read Flags Of Our Fathers, you WILL NOT be disappointed when you do!
Semper Fi