This story is a sequel to Terror in Equestria 5: One Thousand Years Later
Three thousand years have passed since the unmaking of the Dark Goddess Twilight Sparkle and her minions and the world has lived in perfect harmony ever since. An assassination of a high level officer near an international border along with deteriorating economic conditions in a couple of nations will bring that peace to an end. This will bring about a terrifying war, the type that the world has never before seen.
In the end, the use of never before used spells which cause horribly unimaginable damage will cause dark forces from the distant past to return, causing the world to transition from one war straight into another.