CHAPTER: America at War: World War I in World War I Era[All sections required.]Economic and human costs of World War I and political consequencesWorld War I killed more people (more than 9 million soldiers, sailors, and flyers and more than 5million civilians), involved more countries (28 nations), and cost more money ($186 billion indirect costs and another $151 billion in indirect costs), than any previous war in history. It wasthe first war to use airplanes, tanks, long-range artillery, submarines, and poison gas. It left atleast 7 million men permanently disabled. Four years of war killed a million troops from theBritish Empire; 1.5 million troops from the Hapsburg Empire; 1.7 million French troops; 1.7million Russians; and 2 million German troops. The war left a legacy of bitterness thatcontributed to World War II some 21 years later.How the war beganOn June 28, 1914, a car carrying Archduke Franz Ferdinand, heir to the imperial Hapsburgthrone, made a wrong turn. As the car came to a halt and tried to turn around, a nervous teenagerapproached from a coffee house, pulled out a revolver, and shot twice. Within an hour, theArchduke and his wife were dead.Gavrilo Princip, the 19-year-old assassin, was a Bosnian nationalist who opposed the dominationof the Balkans by the Austro-Hungarian Empire. He had received his weapon from a secretsociety known as the "Black Hand," which was clandestinely controlled by the government ofSerbia. Princip died of mistreatment in an Austrian prison in 1918.The assassination provoked outrage in Austria-Hungary. The dual monarchy wanted to punishSerbia for the assassination and to intimidate other minority groups whose struggles forindependence threatened the empire's stability. The assassination of the archduke triggered aseries of events that would lead, five weeks later, to the outbreak of World War I. When theconflict was over, between 9 and 15 million people had been killed, four powerful Europeanempires had been overthrown, and the seeds of World War II and the Cold War had been planted.A complicated system of military alliances transformed the Balkan crisis into a full-scaleEuropean war. Recognizing that any action it took against Serbia would create an internationalincident, Austria asked for Germany's diplomatic and military support. Meanwhile, Russia,fearful of Austrian and German expansion into the Balkans, strongly supported the Serbs andbegan to mobilize its army.This move made Germany's leadership fear encirclement by Russia and France. Germany sent anultimatum to France asking it to declare its neutrality in the event of a conflict between Russiaand Germany. The French refused. They were obligated by treaty to support Russia and were stillbitter over their defeat by Prussia in 1871. When Russia failed to demobilize its forces, theGerman Kaiser agreed to war.