The book is an actual deep philosophical piece with war as the central pillar all the thoughts are based around. Its raises a lot of questions, and portrays a lot of its points as superior, but you can still find flaws within it to disagree with and question if its truly as wonderful as it appears.

The movie tries to only portray a single point of view, with so little subtlety it doubles back and becomes a mockery of itself. Which manages to cancel out and just leave an awesome action movie.

He also added the entire love triangle bullshit to the movie, including genderswapping Diz and turning Carmen from a throwaway character, entirely because he thought that little of Americans.

Ironic that its the only part of the movie everyone agrees was awful and tacked on garbage (sans the extra titties).