It's important to realize that the U.S. could destroy the earth(turn it into an asteroid belt) 12 to 50 times with present weapons

This is all by itself with no help from even one other nation. This is just the U.S. military

Russia can destroy the earth (turn it into an asteroid belt) at least 12 times also.

China all by itself could turn the world into an asteroid belt many times as well.

Understanding this you get why economic sanctions are used instead of war to avoid human extinction and the extinction of all life on earth and the end of Planet earth by turning it into an asteroid belt like Maldek (our present asteroid belt) was a planet turned into an asteroid belt 65 million years ago by our space  faring ancestors.

But, this is also why we have time space travel to erase nuclear blasts too and weapons beyond this too. So, we have regular retroactive time travel here on earth. And it isn't just the U.S. that has this either.

So, the most extreme weapon is Not being able to end earth 12 to 50 times all by ourselves. And it isn't just retroactive time travel that we have too now from off world sources, it is even beyond that as well.

The average person on earth cannot fully comprehend the fullness of ANY of this!

So, mostly at this point it is WHO decides to do What and When.