I know why this civilisation came to an end.
There is a song in my village that I now know was teaching this wisdom.
“Set down the root and live in harmony with the breeze.
Let us endure the Winter like the seeds in the frozen land,
and sing in rejoice with the birds in come Spring.”
You cannot justify for the king to sustain when the whole kingdom has perished. No matter how powerful the weapon you built, no matter how many robots you enslaved, you cannot live without having the roots in the ground.
( Hayao Miyazaki – Castle in the Sky)