The same could be said of almost every nation. They were all lusting for war. There was a interlocking series of alliances that assured any war would be over the top, even tho they claimed those alliances would make war impossible.
Serbia actively encouraged and aided the Black Hand, the group that Assassinated the Archduke- which was a insanely stupid thing to do (The Archduke was actually pretty liberal). Solid evidence that the Black Hand was part of Serbian Military Intelligence, or perhaps just one of their orgs. Serbian troops cross the AH border before War was declared, making the issue even worse. Altho the Demands were Onerous, both GB and France suggested they agree. **Fault lies with Serbia. **
Austro-Hungary was tired of “Yugoslavian” separatists, the terrorism, the uprising, anarchists, etc. The government was old, tired and unstable. They deliberately over-reacted to Serbia’s Casus belli . Fault lies with A-H.**
Russia was slavering to add more of the Balkans to it’s empire, thinking that could solve unrest at home. They wanted to go to war, wanted to seize more of the balkans, and thought AH was a easy target.** Fault lies with Russia.**
France was eager to avenge the Franco-Prussian war and to seize back Alsace Lorraine. They mobilized early and aggressively, planning on attacking Germany while Germany was busy with Russia. **Fault lies with France. **
And so forth.
WWI was a clusterfuck. Certainly Germany shoulders the blame- about 1/6th of it. Saying is was Germany fault is overly simplistic.