Psychological Warfare:
"The planned use of propaganda and other psychological actions having the primary purpose of influencing the opinions, emotions, attitudes, and behavior of hostile groups in such a way as to support the desired objectives."
Blow n gasket, I couldn't agree more. Maybe to summarise what you said in your post, this is what is meant:
"The great enemy of the truth is very often not the lie - deliberate, contrived and dishonest, but the myth - persistent, persuasive and unrealistic." JFK