Originally posted by: So
Any cogent analysis of WWI's causes will agree that while Germany is far from solely responsible for the war, they were certainly itching for a fight and bear the brunt of the responsibility.
Austria was pissed because of the heir being assassinated, which was to be expected due to their imperialism in the region.
Russia wanted to further spread its influence through the Balkans (always after that warm water port) and eventually to take over Turkey.
Russian troop buildup / mobilizations against Germany AND Austria served to cause the war to spill over into the rest of Europe, plus Germany / Russia had a sub par leader at the helm, that always helps.
France would not mind having payback for the Franco-Prussian war defeat (and now she had allies).
Britain did not like rivals (and Germany was directly challenging her naval superiority) and they would not mind gaining control over select German colonies abroad. German aggression to neutral nations put them over the edge (Germany wanted to end the war quickly by knocking the French out of the war via a surprise attack through Belgium, which was a violation of her neutrality of course).
Unrestricted submarine warfare was the main factor in the US getting involved. The Zimmermann telegraph was another factor, which was dispatched because of the rising tensions. Lusitania caused an outrage, but we know that the ship was carrying civilians and ammunition / war materials (it does not justify the killing of innocents, but I think both sides were in the wrong there, for I am personally against using a ship to carry civilian passengers and war materials at the same time).
World War I was caused by massive blunders from nearly every nation involved.