In , the United States Marine Corps is the main protagonist's faction. The player controls Marine Staff Sergeant of Misfit Squad, in the single-player campaign. He is controlled in most singleplayer missions, in an effort against the Iranian , in the year 2014. They eventually come into a quick skirmish with the Russian Paratroop, the VDV, in the mission Rock and a Hard Place.
In , the United States Marines Corps makes a brief appearance in two singleplayer missions: , where the player is part of a World War II Marine operation against the IJN, and in , where Bad Company gets support from the modern Marines against forces. The modern Marines all use the same character model as the 's model from multiplayer.
The United States Marine Corps are masters at amphibious warfare and have existed in some form since the American War for Independence. No doubt this long combat history will serve them well against the Martians when releases them along with special rules.