In homogenous cultures, the prevalent ideology that secures social stability must be maintained, but advertising it is not necessary. Unity and stability are the goals, which requires mass events and a little witch-hunt, but that's the end of it.
Nazi Germany still used the tools of propaganda in the traditional manner, and Goebbels still held that good propaganda is based on the truth.
Stalin’s Soviet Union already employed most devices easily-discernible in today’s “covid” mass hypnosis with people kept busy trying to explain their Stockholm syndrome. Stalin didn’t care what his subjects believed as long as they obeyed. In order to ensure his realm of terror, his maxim was that “if you punish the innocent, everybody is afraid.” Sounds familiar?
The age of propaganda is relatively new, first made possible by radio broadcasts. It is not even particularly expensive, if the taxpayer pays for it, as is the case these days in western “democracies.” It became necessary only after the eradication/disruption of cultural continuity.
The truth has been irrelevant in the political theater at least since Machiavelli. Modern science is not interested in the truth, either. The only criterion to test "scientific" paradigms and theories is based on their usability (explanatory power included), which is not measured by "scientific" standards, but by the returns from which the rulers can benefit.
Lately, propaganda*, as far as I can see, has been turning redundant, because the masses are being conditioned by being incarcerated between fear and hope, which ultimately makes them docile and dependent on their torturers, who offer "protection" as all good racketeers do. It's working**...
*Propaganda is a modern term, which retroactively projects the ulterior motive of mass manipulation. Traditional cultures were often multilingual, but they did not allow for "multiculturalism." Propaganda has not always been around, as opposed to the prevalent ideologies that were enforced in order to maintain social stability.
Culturally prevalent ideologies didn't need propaganda, because they were enforced by the rulers. Ideology and propaganda are two different things with different functions in culturally-specific segmentations. While you didn't have to believe in an ideology, you had to pretend you did, whereas modern propaganda is targeting those, who an uncertain, insecure, or do not believe in anything. Today's West is beyond propaganda and is back at ideology, because people are no longer need to be convinced; enforcement is more than enough.
**Stegiel called my attention to a few more details that must be mentioned.
From the original text, I omitted the importance of printing, which is, to a certain expent, a game-changer. Flyers, the predecessors of newspapers, were circulating after Guttenberg as soon as industrially-manufactured paper became cheap enough for the task (Defoe's Robinson Crusoe was inspired such a three-page pamphlet).
Also, it was the year 1789, when the traditional ideology, religion, was replaced with nationalism, although nationalism had not even existed before as a unifying concept applied to people speaking the same language. It must be noted that it was Protestantism that first vindicated the significance of the vernacular.
All in all, in 1789, a major change in ideology was born, and religion never fully recovered as the prominent one. It can be safely stated that propaganda was necessary for the "Enlightenment," and it managed to reach the most important target audience, influential and literate people, as well as the masses, who served as cannon fodder for the new ideology. Although the corresponding nationalistic "revolutions" of 1848 were defeated, just like Napoleon succumbed to his diet of homemade food laced with arsenic on the Isle of St. Helen.
The next ideology, Scientism, was born with Comte's writings, but didn't prevail until the 1880s, so until this very day, Religion, Scientism, and Nationalism are concurrently used for filling the empty heads of present or future victims of the rulers.
This story is a lot more nuanced than my previous version.
Ray, my favorite all time bumper sticker from the early 70s said:
"GIVE: To support the helpless victims of Computer Error!"
It was fear then, and it is fear now.
But you know what, I'm not scared.
It's not working here. I doubt that it is in Queensland and Victoria either, where we're told that we all should wear masks. Compliance is a minority of upper middle class. Everybody else has had jack-shit of it.
And propaganda is a lot older than Marconi. The Greeks and Romans were very good at it, much better than this 21st Century crowd. But it still relies on force to put in place a 'new paradigm'.