This war film was one of the early "super cynical" war films.
Don't be mislead by that category. There have always been cynical war films. Most books made into films were about the disillusionment-ALL QUIET ON THE WESTERN FRONT, THE RED BADGE OF COURAGE, and so forth.
But Hollywood has always been biased towards the cynical. In the late sixties, they got very self righteous and arrogant about it.
This film, one of the early "super cynical" films was different than the usual Hollywood fare. It dealt with the cynicism credibly. The characters have very credible motivation, instead of the usual Hollywood "Oh love me cause I'm full of cruelty" characters with no motivation.
In this film set during the second world war, a published writer has made a livelihood on the exploits of a war hero. He has never met the man, so he decides to play war correspondent and get first hand details.
That's when he finds this "war hero" isn't heroic, but rather an anti hero of sorts. He plays to win, period. This means some cruel ways, which is war. Does he go too far? Probably not as far as Hollywood wants to take it, but he does it in a believable way.
The film takes turns, and has an unexpected ending. Certainly not a Hollywood hate formula ending.
This is a great war film in my opinion.