ww3 might exist for a few days before the nukes drop. Then it'll be the end of the world, and not ww3.
you know the book of revelation in the bible? it said that fire would rain down and there would be 3 days of darkness, the 3 days could be a nuclear winter and the fire could be nukes. There's litarally nuclear war in the bible.
In fatima, portugal, there was a series of apparitions around 1918, in which mary said that the world's punishment would come from russia
even if you aren't religious, it's not hard to believe this is probably the end of the world