Is this even a fair question to ask? This seems to be a debated topic, or maybe I'm just ignorant on facts. If you ask me, I blame Serbia. If not I'd go to Austria-Hungary. I could also see basically everyone being blamed, as all countries seem to have piggy-back'd with their allies. If anyone's curious, I'm in a debate with my friend who blames Germany for the cause of WW1. Thank you for your responses.