Johnny can shoot who he wants to in the Insurgency game. He can mow down Americans at will if he (or she) chooses as illustrated (click on it for a better look) in one of the screenshots for the game.
The game manual states:
If your play style is more geared towards using real tactics, teamwork, communication, and personal skill, then the Conventional teams will likely be your favorite. If you just want to get into the action and have some fun, grab your AK47 or RPG and let loose as a Guerrilla or Paramilitary fighter. . . .
Engage in urban warfare where every window, doorway or road block is a potential ambush point and every object on the street needs to be watched with care. Fight against the occupation from behind windows and burned cars, with your finger on the trigger and an unsuspecting patrol down the street getting ever closer. Whatever you choose to do, Insurgency is sure to get your pulse racing and make your breathing feel heavy while you engage in such a unique and original combat experience.