Getting Even (1988)

This time they don't have to fight. They want to.

After being betrayed by a fellow Marine and spending five years in a POW camp, homeless Vietnam vet Roy Evans reunites with his commander, Dundee, and is tasked by the FBI to find his betrayer, Slisko, who is suspected of slaying several women. Slisko has also become an arms dealer, and Evans and Dundee endure the trauma of returning to Southeast Asia to apprehend their old comrade