Well, WWI in the scheme of things was like this: before the war countries in the scatter belt would build up armies and and arm it with latest weapons of the time. To an extent they got very prideful and ambitious, mainly pushy and trigger happy. So when Archduke Franz Ferdinand was assassinated, no one was persuasive on the matter of no war.
When it got down and dirty the countries got tired of fighting so they wanted end, except Germany they kept pushing on for the war.
-Its like when siblings play fight and hurt each other they they get serious and real fight that was World War I.