he causes of World War I lie in the intricate alliance system that existed in Europe prior to 1914. The trigger was the assassination of Austrian Archduke Franz Ferdinand in Sarajevo on June 28, 1914. It was duty, not dedication to a cause that brought Russia, Britain, and France to Serbia’s aid while Germany and Austria-Hungary prepared for war. World War I, the “War to End All Wars,” grew out of long-held alliances and resulted in a lost generation, disillusioned by war. Many countries, like the United States, vowed to remain neutral yet were inevitably brought into the conflict in response to German aggression. Despite its isolationist policy, the U.S. ultimately declared war on Germany in 1917. World War I was the first major war where aircraft played a significant combat role. It also set the stage for WWII as German citizens nursed a grudge for decades, feeling that the armistice treated them unfairly and prevented Germany from recovering after the war.