One of Us(1989)

A few Palestinian guerilla's break into an Israeli camp in the occupied territories. They kill a few Israeli soldiers before they are killed, apart from one who dies in the camp after being captured alive. The Israeli military dispatch an investigator to the camp to see if there was cold blooded murder (people at the camp had claimed he was shot while trying to escape). It turns out that the investigator dispatched is a friend of the camp commander - the rest of the plot is basically about the position of both of these characters as regards being honest or faithful to ones friends. There is unbearable tension, increased by the fact that they are both very strongly attracted to one of the female soldiers on the camp.