They seem to me to be a direct reference to pre-9/11 America, or perhaps even post-WWII to 9/11 America. We once ruled the world with good intentions. Everything went our way. The world looked to us for the right path. Then the world changed and America changed. We live in a castle made of sand. We buried the tyrant old kings, only to become tyrant kings ourselves.
"People couldn’t believe what I’d become
For my head on a silver plate
Just a puppet on a lonely string
Oh who would ever want to be king?"