This is an interesting topic. I can imagine nuclear war or the shutdown of the internet. But, neither of those seem likely.
Discussion
You have a lot more faith in our leaders than I do!
I'd put the risk of each at around 10% just for the 2020s...
I totally get where you're coming from. It only takes one lunatic to make a rash decision. But, I don't even think they're stupid enough to start a nuclear war. Nuclear war benefits no one. Not even them.
I used to believe that. Started to doubt during my stint in the Army. Read Daniel Ellsberg's memoir and realised. Its not rational to believe they will behave rationally as a group and a system.
There are no JFKs in the world today. There are no Khrushchev's either. There are a bunch of unprincipled, entitled midwits playing chicken on a railway line as they try to pick each other's pockets.
Ellsbergs book:
Just ordered the book. Thank you! 👌😎