The American campaign starts on the Moon, but the NSDF is forced off after the destruction of their main base. They relocate to Mars, but find the Soviets already there. Both sides locate alien artifacts, and the Americans also find a factory; the long-dead alien race that created the bio-metal is identified as the Cthonians, who inhabited the planet Icarus (now the asteroid belt) and visited Earth on several occasions, influencing Greek mythology. The Americans learn of an ultimate weapon called the "Fury" and head to Venus to learn more about it. Another Cthonian relic is recovered, pointing to Jupiter's moon Io. The NSDF finds a third relic, but this is stolen by a scientist defecting to the Soviets. The player must steal a Soviet fighter craft and tap into the communications network, which reveals the CCA relocation to their main base on Saturn's moon Titan. The Americans clear nearby Europa of CCA units to prevent early warning to those on Titan, but the main assault is annihilated, as the Soviets have begun to manufacture Fury vehicles. However, the Furies turn on the Soviets; they are self-aware and programmed to destroy all life. Icarus was destroyed by the Cthonians to prevent the Furies from reaching Earth. The NSDF and CCA ally against the new threat, and after destroying the production factory on Titan, travel to the fictional moon of Achilles, orbiting Uranus. The Americans destroy the main Fury base, but this causes the moon's core to destabilise, and the player must destroy the Furies' evacuation vessel before it escapes, then escape themselves.