How can civilization end without Nuclear weapons?

 I think civilization wouldn't end immediately. It might take 20 to 30 years for civilization to end. However, after Ukraine destroyed 7 billion dollars worth of Russian Bombers with 1 million dollars or less worth of small Drones (about 900 dollars each and 117 of them) everything has changed in war on earth in various different ways. 

It's sort of like no one thought anyone would turn planes into missiles and bring down the world trade center either in New York with passengers on board either but that happened too.

The same thing happened to Russia from Ukraine blowing up 7 billion dollars worth of Russian Bombers or 34% of their entire bomber fleet in Russia on one day!

Warfare changed both those days in really scary ways for the whole world.

It means people who think outside the box enough can and will do almost anything now with drones, missiles or poison gas.

And what if Iran uses poison Gas in their drones or missiles now too.

It's important that the world basically is prepared for almost anything to happen now.

Pandora's box has been opened by Trump and God help us all! 

It reminds me of the story of the Zen Master and the Chinese Village.

There was a boy of about 12 to 14 years of age. And one day he won a contest and won a beautiful horse and the people said, "Isn't this boy lucky to win this marvelous horse?" and the master said: "We'll See".

Then the boy fell off the horse and broke his leg so he couldn't walk for a long time and the people said: "Isn't this boy unlucky to break his leg falling off this wonderful horse?" 

and the Master said: "We'll See" 

Then all the boys were drafted into the army except the boy who won the horse and broke his let and they all died (all the boys in the village who went to war died).

Then the people said: "Oh. This boy is so lucky he won this horse and broke his leg because he is still alive."

And the master said: "We'll See"

If you have ever studied non-dualism this is a perfect illustration of non-dualism where you really aren't sure where things are going each time.

But, it's also how life is too.

It's like a pendulum when you swing it too far it might came back and hit you in the face and knock you down and kill you.

Or as Isaac Newton says" Every action will cause an equal but opposite reaction."

And right now we are waiting for the reaction.

My personal theory is that this reaction takes out both Iran and Israel permanently with both governments gone (the present governments).

What happens to the U.S. for dropping bunker buster bombs on Iran?

That's harder to guess what happens there. Too many variables going too many directions at present to understand all this fully at present.