For us all to die would involve the big red nuclear button. Nothing is impossible, but I doubt even megalomaniac world leaders would be that MAD (Mutually Assured Destruction).
Despite the advances in military technology, most wars / battles are still mostly localised and mostly fought between the military themselves.
That can and does change as one side starts to see defeat on the horizon. A loosing powerful nation is potentially very dangerous.
An interesting phenomenon that I've noticed. When I am in pain, my wife is more concerned and distressed than I am, and vice versa.
When we understand the danger, we often accept it, but worry for others. So it is with my family. I am much more concerned with the long term safety of my family than I am about my own life. I am older, but even so, I still value my life, but not as much as my families.
This is the planning I am doing right now, securing the future for my family for the next 150 years or 5 generations, as best I can.