I don't know that this is true. Christendom has a longstanding eschatological tradition, but I'm not sure that it's been in any way universal. Cyclical views of long time are pretty common, for example.

Humanity hasn't always had nukes. I think Ukraine/Russia is somewhat likely to go worldwide, and it's going to be hard to stop a large nuclear exchange at that point. I'd be surprised if we have 5 years left.