Assassination: The Spark That Ignited a War

• Historian Barbara Tuchman, in her Pulitzer Prize-winning account of the beginning of World War I, "The Guns of August," noted a complex web of alliances and treaties that bound the major powers of Europe and contributed to the outbreak and widening of the war. The assassination of the heir to the throne of Austria-Hungary was the spark that set off the explosion that was "the Great War." On June 28, 1914, Archduke Franz Ferdinand and his wife, Sophie, were assassinated in Sarajevo by Gavrilo Princip, a reputed member of the Serbian nationalist "Black Hand" movement.
  
  

Ultimatum and Declaration

• Although Ferdinand was hardly a favorite of his uncle, Emperor Franz Josef, the government of Austria-Hungary was not about to let the murder of its royal heir go unanswered. Within three weeks of the slaying, Austria-Hungary presented Serbia with an ultimatum, the demands of which had the effect of infringing on Serbia's sovereignty. The Austro-Hungarian government anticipated Serbia's rejection of the terms, which would provide an excuse for Austria-Hungary to overrun Serbia and assert its dominance over the Balkans. Serbia accepted most of the terms of the ultimatum, but its rejection of a few minor clauses gave Austria-Hungary the excuse it wanted. On July 28, 1914, Austria-Hungary declared war on Serbia. What was intended as a limited war, however, escalated and consumed all of Europe as a consequence of the many treaties and alliances that existed.
  
  

Chain Reaction

• The assassination of Franz Ferdinand and Austria-Hungary's subsequent declaration of war against Serbia set off a chain reaction of events that escalated a regional war into a worldwide catastrophe. Russia, as a friend of Serbia, mobilized its army in defense of its ally. Germany, allied with Austria-Hungary under a treaty, saw Russia's move as an act of war. Kaiser Wilhelm II of Germany declared war on Russia on Aug. 1, 1914. This brought other treaties into play. France, allied with Russia by another pact, found itself at war with Germany and Austria-Hungary. Kaiser Wilhelm II, seeking to crush the French, invaded Belgium, a country recognized as neutral under an older treaty. Britain, allied with France and obligated to defend neutral Belgium, declared war on Germany on Aug. 4, 1914. This, by extension, put Britain at war with Austria-Hungary, as well.
  
  

War Escalates

• In late August, Japan entered the war. The Japanese had a military agreement with the British and declared war on Germany on Aug. 23, 1914. In retaliation, Austria-Hungary declared war on Japan. The Turkish Empire, which had quietly struck an alliance with Germany, entered the war in November 1914, declaring war on France, Britain and Russia. Italy, meanwhile, tried to stay neutral despite an alliance with Germany and Austria-Hungary that obligated it to defend its two allies in a "defensive" war. Italy claimed that the actions of Germany and Austria-Hungary were "offensive" and declared its neutrality. In 1915, however, Italy joined the war against its two former allies. The United States, meanwhile, resisted becoming entangled in the war and declared neutrality until Germany's unrestricted submarine warfare forced the U.S. to enter the war in 1917.