The American campaign follows an NSDF unit, also called the "Black Dogs", during scrap-gathering operations on Jupiter's moon Ganymede. The Americans, expecting boring garrison duty, are ambushed by Chinese tanks, which are capable of cloaking. After being mauled by the Chinese, the Americans reestablish themselves and discover that the Chinese are using a Stargate-like portal to travel between Earth and Ganymede, and to the planet Elysium, which is located in another solar system. Control of the portals changes hands back and forth several times, but the campaign ends with the Americans in control, and the Chinese annihilated. The Chinese campaign starts earlier, with the first few missions focusing on stealing the Portal technology from the Soviets (who do not have their own campaign) and establishing their own. Later missions follow the American attempts to control Ganymede and Elysium.