Hyperinflation was caused by the grossly inept war time economic management so the fault of Germany. Germany was hit so hard because the German Government -deliberately- made the depression worse to get out of paying reparations

And Keynes was wrong. German hyperinflation occurred due to gross mismanagement during the war done by the German government. Germany didn't actually pay hardly anything during the 1920s in terms of reparations but nonetheless complained of its inability to pay while receiving billions in cheap loans which saw its economy show record growth after 1924

The Western Front of the Great War is one entirely of Germany's making. Germany attacked Belgium and France first and it was moreover Germany which pushed Austria-Hungary to present impossible demands to Serbia while telling them Russia would do nothing. The person and indeed the organization which killed Franz Ferdinand - Young Bosnia, wasn't Serbian in origin and its connections to the Serbian Black Hand was dubious and its not like the Austrians ever performed an actual investigation into it. Nonetheless, the Serbian Government tried and executed the entire organization in 1917 because the Serbian Government was just as annoyed by the Black Hand as the Austrians were.