A few months ago I read something about a theory by a scientist (or sociologist?), Italian, I think, along the lines of: the fact that we have found no life on other planets could be due to alien civilisations political structures not having kept up with scientific progress. I.e. those civilisations were advanced enough to create weapons of mass destruction but could not manage them and ended up self-destructing
It's called the Fermi Paradox, after the physicist Enrico Fermi. It is primarily referred to in relation to the emergence of an Artificial super-intelligence.
Which is what makes me laugh a little in response to the hysteria exhibited on this thread. You heap abuse on posturing politicians, but there are software engineers out there (Google Deep Mind, for example) who are busily creating machine intelligence that can, feasibly in theory, extinguish all forms of life on this planet in the blink of an eye - an existential threat to humanity's survival that dwarfs that offered by nuclear weapons. Yet no one bats an eyelid.