From The Soldier's Handbook:
"Behind Enemy Lines is a role-playing game of action and individual Combat set against the backdrop of World War II. Behind Enemy lines allows the players to take on the characters of an infantry squad. Combat involves the characters in skirmishes, patrols, and other small unit actions. that develops a picture of the war from the soldier's point of view."
This Box set contained:
The Soldier's Manual - which contained rules for the generation of characters and the basics of movement and fire.
The Commander's Manual - which contained rules and information on how to run the game
Operations - Which contained six scenarios/encounters.
Infantry Reference Data - a GM's screen