The Iraq debacle was an interesting case study, in that you did have an administration that had a documented white-knuckled grip on their propaganda game. Many of the reigning neocons were convinced that the Vietnam War was lost not because of central held premises and perceptions that were just bad and wrong, but because the government and the media were not properly constructing the right narratives and controlling the flow of information well enough, and that there was a collective failure of will and resolve as a result.
But with Iraq this problem would be addressed: you had a growing bifurcation in which you had an insulated and massaged government control of information and a compliant and cooperative media that manufactured its own reality that, as the war advanced and intensified and the catastrophes racked up and amplified each other, more and more resembled a direct inversion of facts on the ground. At least, until the narrative altogether ran away.
This sort of heavy-handed application of propaganda in a sense lays out a virtual minefield in the communication sphere, which interacts with the reality that communication sphere interacts with and shapes and is shaped by. When the uncorrected narrative eventually comes into contact with reality, it comes into contact explosively and violently, and destroys functional capacity in its wake.
The result was a deeply jaded public that had more and more trouble believing in any sort of public or collectively held reality, and these effects of course are global and would generalize. This is of course nothing new, but it is important to stress that this stuff is cumulative. Trust, once broken, is very difficult to restore. And so a new equilibrium forms around this scene of devastation, and the dynamic picks up where it left off in a weakened and more unstable environment. This was true of the subsequent financial crisis and then the pandemic, and it will be continue to be true until the ruling elite further collapse.