Counterproductive Propaganda

Exactly what it says on the tin, propaganda that is counter-productive to the goals of the group spreading it (or what should be the goals). A common version is to portraying the group’s enemies as stupid, weak, etc… than they are. It is common knowledge that underestimating your enemy is a terrible idea. So encouraging your own side to do this is also a terrible idea. This trope can and (let's face it) will result in those who are loyal to the group spreading the propaganda believing the propaganda, with catastrophic consequences. The survivors of the propaganda's consequences will usually realize how untrustworthy the apparent propaganda source is, and thus are likely to not use information they receive from that source. Which is somewhat a shame, in some cases, because sometimes that same source provides valuable information. Often, the propaganda infects even those that fabricated it.

Subtrope of Propaganda Machine. Compare Not Helping Your Case and Do Not Do This Cool Thing.

Literature

 * The Imperial Infantryman's Uplifting Primer has multiple examples, perhaps the biggest case of this is that it says genestealers are slow and sluggish and have blunt claws.
 * In Fifteen Hours propaganda states not only does the bureaucracy gets its directions from the God-Emperor of Mankind (that is allegedly infinitely wise), but that it passes on these directions flawlessly. This leads to spotted mistakes being ignored, because those mistakes were apparently intentional for whatever reason the observer can come up with. This, unsurprisingly, has catastrophic consequences.

Real Life
"[…] if the Soviet went out of their way to prevent western propaganda from reaching the Soviet people, the Russians are nowadays doing the exact opposite: they are going out of their way to make sure that western propaganda is immediately translated and beamed into every single Russian household. What I propose to do today is to share with you a few recent examples of what Russian households are regularly exposed to. By now, you must have heard about the CNN report about how the evil Russkies used Pokemon to destabilize and subvert the US. If not, here it is: In Russia this report was in[sic] instant mega-success: the video was translated and rebroadcasted on every single TV channel. Margarita Simonian, the brilliant director of Russia Today, was asked during a live show “be truthful and confess – what is your relationship with Pokemon, do they work for you?” to which she replied “I feed them” – the audience burst in laughter."
 * American propaganda portrayed the Japanese as stupid in WWII.
 * Both sides of the American Civil War were prone to this in the beginning. The Union propagandists that with their massive resources of men and resources they could easily overwhelm the South, while the Confederacy propagandists proclaimed they could just shock the Union into surrender because they were utterly convinced the Union's resistance would be token at best. And both sides were convinced the first serious amount of bloodshed on either side would cause the other side to realize the futility of their resistance, an illusion brutally shattered during the First Battle Of Bull Run/Manassas. After that point, both sides realized it wouldn't be that easy to win and changed their propaganda about their enemies accordingly.
 * One theorized motive for World War II Japanese diplomat Chiune Sugihara's helping Jewish refugees avoid the holocaust was Nazi propaganda convinced him Jews were excellent business men, making him see them as potential assets that would help grow his country.
 * The realities of internet led to a curious situation: it's very hard to block or actively counter propaganda, but at the same time risk of backfire for the attacker is very high — and who doesn't have enthusiastic idiots? Most of the contemporary mass media doesn't work well enough to avoid contempt even in USA, and various attempts to implement "divide and conquer" policies (like Google's "this video is unavailable in your country" and Great Chinese Firewall) more annoy people than hide anything from anyone who really wants to see it, so the winning strategy is simple and widespread: among those most hostile to you find a handful of the stupidest, and give them as much of exposure as you can.
 * The American Progressives used to play this trick on American Conservatives (name 3 loons from 70s-90s who should have been village idiots, but somehow got widely promoted), but between a few false flags too many and losing ability to muzzle their own "Holier Than Thou" types, now they are firmly stuck on the business end of this. Every mention of cow farts or "racist code words" is one more fish swimming in a small barrel.
 * On the international scale, it does wonders too:

- Re-Visiting Russian Counter-Propaganda Methods by The Saker on The Unz Review