Answer:
mutual defense alliances, imperialism, militarism, nationalism, and the assassination of Archduke Franz Ferdinand
Explanation:
Europe made mutual defense agreements that pulled them into battle and the following alliances were: Russia and Serbia, Germany and Austria-Hungary, France and Russia, Britain France and Belgium, Japan and Britain. Should one defense alliance declare war on another (ex: Austria-Hungary and Serbia) that would automatically bring Russia into it. Imperialism is when a country increases their power by bringing in territories under their control. The increase in militarism pushed countries involved in the war. Nationalism throughout various countries in Europe contributed to the extension of the war in Europe. In June of 1914, a terrorist group known as the Black Hand assassinated Archduke Franz Ferdinand. This was protest to Austria-Hungary having control over Serbia. This assassination lead to Austria-Hungary declaring war on Serbia.
