1. By 1914, Europe was divided into two alliances - the Triple Entente of Britain, France, and Russia, and the Triple Alliance of Germany, Austria-Hungary, and Italy. 2. Austria-Hungary's declaration of war on Serbia in 1914 pulled the alliances into World War I. Nearly all of Europe was engaged in the massive war by August. 3. The conflict resulted in trench warfare along the Western Front in France and heavy fighting along the Eastern Front between Germany, Austria-Hungary and Russia that tied up hundreds of thousands of troops.