>>512528883
Communism mainly.
The founder of communism (Karl Marx) was a Jew and Jews were prominent in most of the post world war 1 attempted communist revolutions in Central Europe.
The only one they really spend much time on in school is the Russian one but there were attempted communist revolutions in Central Germany and Hungary at the end of the war and this put the axis powers between a rock and hard place forcing them to sue for an early peace so their troops could be sent back to their capitals to surpress the uprising.
Jews were at the forefront of these uprising, thus came the basis for the idea Jews “stabbed Germany in the back” in the First World War.