In 2030, the "shield" satellite system set up by the major powers in space ends the era of ballistic missiles. The danger of nuclear war is no more. In 2035, the United States fell into a great crisis of ethnic and political conflict. An armed conflict takes place within the United States and make lose its global leadership role. In 2040, the world is dominated by 12 multinational military organizations. The conflicts are getting more intense and the world is facing a new world war. The Endwar.
Armored Personnel Unit of USA vs UKA is a high-tech mecha robot. Unlike similar units of the JAF, the Armored Personnel Units of the US and UKA have reduced their anti-aircraft capabilities to enhance their ability to resist tanks and armored vehicles.