ESRB rating description reveals WWII mission in BFBC2

The ESRB has rated Battlefield: Bad Company 2, and in the ratings description, it notes that at one point the player is fighting in World War II.

In single-player mode, players conduct missions on an unnamed Japanese island during World War II and then move into the modern day through jungles, deserts, and snowy terrain.

This was to be expected seeing that the Thompson and M1 Garand are weapons available for online play in Bad Company 2.

BFBC2 drops in March.

Source