I know I've seen this before but the first and only thing that comes to mind is the movie "Jarhead" about Operation Desert Storm. The marine are all pumped up to go shoot some bad guys, but they get to Iraq and battle with frustration, boredom and isolation instead. A lot of people didn't like, but I found it very different, and good. Definitely shows what happens when characters are groomed to meet the opposing forces, and no antagonist(s) ever show.