I remember the end of this movie had two men/ soldiers pinned down behind a barricade, surrounded by some kind of army that kept pulling up more vehicles and people, it was a tropical setting either South America or South Pacific.  The soldiers (or two men fighting) talk to eachother about how hopeless it is, and decide the only option is full-scale assault.  They pitch grenades back over the barrier and start shooting.  They survive – I think the end of the movie has them on crutches back home being congratulated.  It was awesome, can’t remember anything else about it!