VI-1 "Nova"

In a alternate timeline where the Axis powers dangerously approach victory, the USA, in a desperate attempt, creates a weapon capable of destroying entire cities with extreme precision, when Germany and the rest of the Axis powers destroyed almost all countries in Europe, this nuclear missile was launched by a secret base in Africa, when it exploded inside Germany's territory, the Axis reacted in a radical way, building another missile, probably more powerful than VI-1, when it exploded on USA and other allies, it had massive effect, but the allies didn't gave up, they created multiple missiles and nukes, creating a nuclear war, causing nuclear winter and the extinction of humanity on this timeline. (sorry for bad english, it's my second language)