"15 years ago, there was a war. Well... war's broken out here plenty of times before. They've tried to invade the south lands through the northern valley time and time again. Luck was never on their side, though, and their victories didn't last long. They didn't realize that times had changed. Facing one defeat after another, losing territory and watching their nation dwindle, they built up their industrial strength to unprecedented heights and used it to wage one final battle against the world. That was 15 years ago... They fought ferociously, but were utterly defeated. The Belkans then committed the unthinkable—they used nuclear weapons on their own soil. Seeing this tragedy unfold before their own eyes, the victorious countries vowed to throw down their weapons. The world was once again at peace. And thanks to them, it seemed it would last forever. On a distant island, far away from civilization, the protectors of the peace take to the skies."
January 1, 1970
https://en.wikiquote.org/wiki/Ace_Combat