[PoignardAzur]

They believed the "stabbed in the back" narrative like the US establishment believed there were weapons of mass destruction in Irak.

It was a motivated belief, thoroughly uninformed by rational thought, and maintaining and spreading that belief took no small amount of blatant lies and cynicism.

[bsdpufferfish]

Stabbed in the back, doesn't explain why facism was a popular world view across Europe and Japan.