"No powerful authoritarian countries except for former authoritarian european colonial powers and their former slave colonies"

What have the slave colonies done?

And any nation that hasn't had colonies, or been authoritarian at some point in their history, has a very short history.

Should we still be judging the Nordic countries based on how the Vikings behaved?

Are you claiming the US to be whiter than white? How many EU war criminals do you think there are to be prosecuted? Do you have any names?