Read the book by Bernays, entitled Propaganda.
Its purpose was actually quite benign: The office in the Vatican was created to offset the Protestant movement.
It was only refined to mass media during WWI; and then refined as advertising during the 1920s. Anyone who took an advertising class in college should have read the book and understand the persuasive art.
Honestly, anyone who understands the basics can see through the BS on both sides. Because it coms from both sides.