Examples of said “dehumanizing propaganda”?
Well, a search with „American propaganda World War One“ will turn up many items. 🙂
As for the British effort, the first major atrocity propaganda since the Thirty Years‘ War, there is this article.
https://en.wikipedia.org/wiki/British_propaganda_during_World_War_I
Still, all of it was so over the top that in 1924, Prime Minister Lloyd George issued an apology to the German nation. He was a good, honest man at heart.
And interestingly, that is why in the Second Great Unpleasantness, such atrocity propaganda was not resumed. Sadly, though, this helped to discredit the reports of escapees from occupied Europe on the fate of the Jews. The Karski report comes to mind. At first, many politicians likened this and similar reports to the boy crying wolf.
Another, not so flattering factor was antisemitism among the citizens of the Allied nations. That’s the reason why allied propaganda in WW2 ultimately decided against using the genocide of the Jews as a means of anti-German propaganda. They feared that too many individuals on the Allied side would begin to sympathize with the Axis on account of their own anti-Semitism. It was not until the camps were liberated that they had been right this time…
Unfortunately, some people today still take thie WW One atrocity propaganda at face value, obviously, but they may be somehow mentally aberrant.
Some don’t seem to know that propaganda has (usually) nothing or nearly nothing to do with facts. Propaganda, by its very nature, is applied to elicit an emotional response, not a rational one.
Well, but so am I, though I don’t believe in that propaganda stuff.