Lasting from 1914 to 1918, World War 1 claimed over 16 million lives, bolstered military technology, and brought world powers to the European theater to fight till ultimate destruction. Who can be blamed for the carnage seen throughout this conflict?
Both Austria-Hungary and Germany are responsible
Austria-Hungary and Germany saw an opportunity to conquer and took it
Austria-Hungary was waiting for an opportunity to assert their influence and their allyship with Germany guaranteed them a "blank check," assuring Germany's support and resources to Austria-Hungary's prerogative.
With aggressive foreign policy and ulterior motives, Germany is guilty of the war outbreak by bolstering tensions and whispering in the ears of their allies.
Germany coerced their ally, Austria-Hungary, to begin conflict
Without the coercion from Germany, Austria never would have gone through with retaliation following the Assassination. As the only war to have been caused by assassination, Germany was certainly whispering to provoke an overreaction.
The Black Hand Serbian Society and the Bosnians are responsible
Increased Serbian Nationalism led to the incitement of conflict
As a region consistently occupied by outer forces, Serbian nationalism in the Balkans peaked in the days before World War 1, and the Assassination of Archduke Ferdinand, which ultimately resulted in the spiraling conflict was World War 1.
Conflicts over alliances dragged all powers in, creating a global conflict
A great majority of world leaders at the time were related, and more notably, their nations were all intertwined through a system of tight treaties and agreements in which actors would fearlessly support those they had agreed to flank in conflict.