World War I was a military conflict from 1914 to 1918. It began as a local European war between Austria - Hungary and Serbia on July 28, 1914. It was transformed into a general European struggle by declaration of war against Russia on August 1, 1914 and eventually became a global war involving 32 nations. Twenty - eight of these nations, known as the Allies and the Associated Powers, and including Great Britain, France, Russia, Italy, and the United States, opposed the coalition known as the Central Powers, consisting of Germany, Austria - Hungary, Turkey, and Bulgaria. The immediate cause of the war between Austria - Hungary and Serbia was the assassination of the Archduke Franz Ferdinand on June 28, 1914, at Sarajevo in Bosnia by Gavrilo Princip, a Serb nationalist.On July 28 Austria declared war against Serbia, either because it felt Russia would not actually fight for Serbia, or because it was prepared to risk a general European conflict in order to put an end to the Greater Serbia movement. Russia responded by partially mobilizing against Austria. Germany warned Russia that continued mobilization would cause war with Germany, and it made Austria agree to discuss with Russia a possible change of the ultimatum to Serbia. Germany demanded, however, that Russia demobilize. Russia refused to do so, and on August 1, Germany declared war on Russia.The French began to mobilize on the same day. On August 2, German troops invades Luxembourg and on August 3, Germany declared war on France. On August 2, the German government informed the government of Belgium of its intention to march on France through Belgium in order, as it claimed, to prevent an attack on Germany by French troops marching through Belgium. The Belgian government refused to allow the passage of German troops and called on the witnesses of the Treaty of 1839, which guaranteed the justice of Belgium in case of a conflict in which Great Britain, France, and Germany were involv...
