"Sniper" expresses a cool competence that is a pleasure to watch. It isn't a particularly original film, but what it does, it does well. We've seen so many bad movies about guys walking through the jungle with rifles that it's interesting the way this one grabs us through its command of the locations and its storytelling skill.
They're hired as a team, to knock off some bad guys, and along the way a rivalry develops, until at the climax their very lives are threatened.
The movie gives this formula a modern political touch by making both Berenger and Zane U.S. military men, acting under secret orders from the National Security Council. Their assignment is to knock off Panamanian leaders the NSC doesn't like, in order to change the outcome of approaching elections. The film's director, Luis Llosa, is a Peruvian, and perhaps this subplot about Yankee imperialism was appealing to him, but the movie simply accepts the illegality of the assignment and gets on with it.