For a millennium, three opposing forces of humanity have fought a bitter and bloody war over their conflicting and unwavering beliefs. There is no room for compromise. No room for mercy. No room for anything but the complete eradication of all opposition.
The Infinite War has ended, however peace did not ensue. A new enemy has risen, humanity must unite and fight this terrible foe.
Remember Total Annihilation? Well, imagine that, but times 1000. And what you have is Supreme Commander.