I watched this 15-20 years ago on PBS (USA), but it looked like it might've been from the late 80's, early 90's. A group of American soldiers have a camp in the woods or a jungle and I think it's towards the end of whatever conflict is going on and there's not much to do.
Things I remember:
- Everyone is outside washing up at a long basin. They complain that they have no hot water, and maybe get scolded for speaking up.
- The squad consists of ~15 guys
- Towards the end of the movie they decide to crash a fancy party being thrown by the enemy (to get some plans or something I think) at a big mansion
- The Americans have one guy with dark hair who can speak the enemy's language. At the party he and a senior officer are approached by one or two attendees. After they exchange awkward words with the enemy he admits to his CO that he's not as fluent as he thought and that he didn't understand most or all of what they said. I can't remember if it was German or Russian, but definitely one or the other.
- I believe they steal/destroy whatever it was they were looking for