Causes of World War I

In the early 1900s political tensions in Europe were increasing. Rising nationalism encouraged new nations to unify and establish their power in the world. On the other hand, it caused some ethnic groups to demand separation and nations of their own. At the same time, established nations wanted to expand their empires and competed with one another for colonies in Africa, Asia and other parts of the world. In order to protect their interests, European nations built up their armies and navies. Along with the military build-up, nations also started forming alliances, or defense agreements. These alliances were aimed at maintaining a “balance of power” in order to prevent war. In reality, it had the opposite effect by having groups of nations agreeing to go to war if one of their members were attacked. If an attack occurred, it guaranteed the spread of war.

In the Balkan Peninsula in southeastern Europe, nations were arguing over territory, while Slavic nationalists wanted to unite all Slavic peoples. In Austria-Hungary, the Slavs wanted independence and the neighboring nation, Serbia, supported the Slavs, causing increased problems between the two nations. On June 28, 1914, the heir to the Austria-Hungary throne, Archduke Franz Ferdinand, and his wife were assassinated by Gavrilo Princip, a member of a terrorist group that plotted the assassination as a way to advance the cause of Slavic unification. As a result, the rulers of Austria-Hungary, blaming the Serbian government, declared war on Serbia. Because of the system of defense alliances among the European nations, the war quickly spread across the continent.