Under "Community and Extras", press "Y" on "Downloadable Content". Battalions can be used in Theater of War mode.

Password	Effect
EUCA20	Unlock Upgraded European Federation (EFEC) Battalion
JSFA35	Unlock Upgraded Joint Strike Force (JSF) Battalion
SPZT17	Unlock Upgraded Spetznaz (Russian) Battalion
SPZA39	Unlock Upgraded Spetznaz (Russian) Battalion