It is worth noting that Keith Gordon (director) met with William Wharton (book author and war veteran) on several occasions and was left with the impression that the 'story' Wharton told is true. Neither author or director could use the 'based on a true story' epitaph simply because the events are completely unverifiable; but reading the book -- and watching the film to a certain degree -- does give a sense that these events did occur.
Knowing that the film is a reasonably accurate portrayal of real events -- William Wharton was said to be impressed by the final cut -- makes the events portrayed in the film even more moving. It also explains why the director chose to focus on certain scenes to keep the story flowing, it was as if he wanted to commit the 'story' to film before it was forgotten.
Having said that, there are touches of directorial brilliance and subtlety in this bleak and wintry tale. For example, the panning shot of the squad of soldiers walking through the forest which finishes with the still picture of a frozen hand -- if you even notice it -- is unforgettable.
These were true events according to the author; it is worth keeping that in mind when you watch the film.