In war "it is necessary to invent lies about the enemy":
"During the First World War most countries publicized stories of enemy soldiers committing atrocities. It was believed that it would help persuade young men to join the armed forces. As one British general pointed out after the war: "to make armies go on killing one another it is necessary to invent lies about the enemy". These atrocity stories were then fed to newspapers who were quite willing to publish them. British newspapers accused German soldiers of a series of crimes including: gouging out the eyes of civilians, cutting off the hands of teenage boys, raping and sexually mutilating women, giving children hand grenades to play with, bayoneting babies and the crucifixion of captured soldiers." 
With Executive Order 2594, U.S. President Woodrow Wilson established the "Committee on Public Information" to propagandize Americans into supporting U.S. entry into the war.
"Germans were referred to collectively as the “Hun” and the “Prussian Python.” Political cartoons and posters conveyed the image of a raging beast ready to devour innocent women and children. Earlier British propaganda was released accusing German soldiers of bayoneting Belgian babies as they marched through that neutral country."
A second propaganda technique used by the CPI was demonization of the enemy. "So great are the psychological resistances to war in modern nations," wrote Lasswell "that every war must appear to be a war of defense against a menacing, murderous aggressor. There must be no ambiguity about who the public is to hate." American propaganda was not the only source of anti-German feeling, but most historians agree that the CPI pamphlets went too far in portraying Germans as depraved, brutal aggressors. For example, in one CPI publication, Professor Vernon Kellogg asked "will it be any wonder if, after the war, the people of the world, when they recognize any human being as a German, will shrink aside so that they may not touch him as he passes, or stoop for stones to drive him from their path?"
A particularly effective strategy for demonizing Germans was the use of atrocity stories. "A handy rule for arousing hate," said Lasswell "is, if at first they do not enrage, use an atrocity. It has been employed with unvarying success in every conflict known to man." Unlike the pacifist, who argues that all wars are brutal, the atrocity story implies that war is only brutal when practiced by the enemy. Certain members of the CPI were relatively cautious about repeating unsubstantiated allegations, but the committee's publications often relied on dubious material. After the war, Edward Bernays, who directed CPI propaganda efforts in Latin America, openly admitted that his colleagues used alleged atrocities to provoke a public outcry against Germany. Some of the atrocity stories which were circulated during the war, such as the one about a tub full of eyeballs or the story of the seven-year old boy who confronted German soldiers with a wooden gun, were actually recycled from previous conflicts. In his seminal work on wartime propaganda, Lasswell speculated that atrocity stories will always be popular because the audience is able to feel self-righteous indignation toward the enemy, and, at some level, identify with the perpetrators of the crimes."
British Army propagandists fabricate story that Germans used the corpses of their dead soldiers to make soap:
"One of the most notorious pieces of anti-German propaganda was the gruesome account of the “corpse exploitation establishment” operated behind the front lines by a German company. The “evil Germans” supposedly used the corpses of their own fallen soldiers for the manufacture of soap. Professor van Pelt notes that the author of this piece of lying propaganda was the Chief of Intelligence of the British Army, Brigadier General J.V. Charteris. Apparently, one of his aims was to turn the Chinese, who revere the dead, against the Germans."
A detailed account of the “corpse exploitation establishment” appeared in the respected British newspaper, The Times, on April 17, 1917. According to the story, trains full of corpses arrived at a large factory. The bodies were attached to hooks connected to an endless chain. The article states:“The bodies are transported on this endless chain into a long, narrow compartment, where they pass through a bath which disinfects them. They then go through a drying chamber, and finally are automatically carried into a digester or great cauldron, in which they are dropped by an apparatus which detaches them from the chain. In the digester they remain from six to eight hours, and are treated by steam, which breaks them up while they are slowly stirred by the machinery.”
The article continues:“From this treatment result several products. The fats are broken up into stearin, a form of tallow, and oils, which require to be redistilled before they can be used. The process of distillation is carried out by boiling the oil with carbonate of soda, and some of the by-products resulting from this are used by German soap makers. The oil distillery and refinery lie in the south-eastern corner of the works. The refined oil is sent out in small casks like those used for petroleum, and is of yellowish brown color.”
(The reader should note the meticulous detail!)
“It was a lie,” Dr. van Pelt emphasizes, “but it was plausible, and it was not possible to completely refute it during the [First World War].”
World War I: Anti-German Propaganda
WWI Anti-German Atrocity Propaganda Used As Model for WWII Anti-German Atrocity Propaganda
In fact, some of the Allied atrocity propaganda from the First World War found its mirror image in anti-German atrocity propaganda promoted by Zionist groups and other Allied sources in the Second World War.
In the August 21, 1944 issue of Time, there was the “first eyewitness description” of the “Nazi extermination camp” at Maidanek concentration camp in Poland...
The article reads:“In the center of the camp stands a huge stone building with a factory chimney—the world’s biggest crematorium. The Germans attempted to burn it but most of it still stands—a grim monument to the Third Reich.”
“Groups of 100 people would be brought here to be burned almost alive. They already had been stripped and then chlorinated in special gas chambers adjoining. The gas chambers contained some 250 persons at one time. They were closely packed…so that after they suffocated they remained standing…The human cargoes were dumped into a roaring furnace heated to 1,500 [degrees] Centigrade…[emphasis added].”
Further on “eyewitness” Karmen claims: “It is difficult to believe it myself but my eyes cannot deceive me. I see the human bones, lime barrels, chlorine pipes and furnace machinery…[emphasis added]."
The Holocaust lobby now claims that Maidanek inmates were murdered with Zyklon B/hydrogen cyanide and carbon monoxide, so the allegation that chlorine gas was the killing agent is false.
But even more importantly, consider Time's and Karmen’s description of how the corpses of the “murdered ones” were put to use: “The victims’ charred bones and ashes were moved into an adjoining department where an incredible process went on. These human bones were mechanically pulverized, placed inside large tin cans and shipped back to Germany for fertilizing the fields.”
This is false propaganda, as there is not one iota of credible evidence to support it. To be sure, the Holocaust lobby no longer claims that there was a “fertilizer factory/corpse exploitation establishment” at Maidanek, where human remains were processed, canned, and then sent back to Germany to be used as fertilizer. Yet, the reader should note how the story is strikingly similar to the aforementioned “corpse exploitation establishment” story of the First World War that van Pelt admits to be a lie. In the WWI version the corpses were utilized to make soap; the WWII version claims the bodies were used for fertilizer.