If one can believe Lucas at all, his earlier statements that Vader and the Empire were modeled after Nixon and the Vietnam-era US industrial military complex.
The development of Anakin into Vader, especially when adding in the Clone Wars filler series (material that really should have been covered in the movies, but is still considered "canon"), is pattered after Vietnam vets' PTSD.
If you read “The Secret History of Star Wars,” you will read, exhaustively, about how Darth Vader was never intended to be Luke’s father until he was written that way in a revised version of The Empire Strikes Back...but Lucas now claims he intended it that way all along. Even though there are previous drafts of scripts of both movies that say otherwise.