Well for starters, most of the modern technologies used in war today can be traced back to this conflict; it was the first time submarines, tanks, man-portable automatic weapons, or aircraft were used in conflict. Additionally, the Ottoman Empire ceased to exist as a result of the Great War, and the treaty of Versailles inadvertently set things up for the Nazis to eventually come to power in Germany, and thus start World War 2. Afterwards, many thought that war had become so horrible that it would no longer take place; thus some called it "The War To End All Wars."
