The First Alien War was a desperate conflict between the human race and the Cydonian Invaders, and the setting for the events of X-Com: UFO Defense. This war involved many clashes with the alien war machine, including shooting down and/or recovering UFOs, alien terror attacks on suburban towns, raiding Alien Bases, retaliation attacks on X-Com Bases, and ultimately a direct attack on the alien stronghold at Cydonia. Humanity was saved. The world was safe from alien incursion. At least for now...