The Walnar Group

The plot concerns a unit of US marines operating in the Vietnam war during 1970, with the movie opening on a raid in a village. After massacring the villagers, the marines steal the villages gold, much to the objection of their Vietnamese translator and guide. Skip forward past the credits sequence; it's now 15 years later, and members of the unit are getting murdered one by one. This leads to the former head of the group, now a high ranking military officer, announcing that the only person who is up to the job of finding out the identity of the killer is an Aussie, Major Brad Cooper.