Afghanistan is the setting for this map and you will be fighting against the Taliban. Combat will be outdoors and indoors, therefore you will need to be efficient in your CQB and open combat skills. Here you can use the M4 Carbine, if you choose to be a rifleman class.
The M4 Carbine is similar a smaller assault rifle with 80% commonality with its older brother, the M16A2. Mountainous terrain and darkness will provide cover for both sides. (Therefore your players must be careful where you are throwing grenades as on Bridge Crossing.)