Let's change the "stab in the back" myth a bit. Instead of blaming unnamed people Hindenburg decides that the country needs a single person to blame for the war and that will unite the country more than anything else. He picks Zimmermann as his actions were largely responsible for getting the biggest economy on the planet involved. He says something like "He and he alone is to blame for the loss of the war. It was Zimmermann who pushed through the idea of trying to align with Mexico of all countries and admitted it not once but twice in the United States thus bringing the World's largest economy against us. We knew the Russians were about the leave the war when Zimmermann stupidly admitted the existence of the telegram so again he and he alone is to blame for Germany's defeat. "