After 1870, the possibility of war loomed over Europe. The Great Powers formed unstable alliances with each other that pitted France, Britain, and Russia against the Triple Entente of Germany, Austria-Hungary, and Italy. After a series of crises in the Balkans, war broke out with the assassination of Archduke Francis Ferdinand, the heir to the Habsburg Empire, in 1914. Hopes that the war would end quickly dissipated as the warring powers settled into a stalemate. Russia, facing internal pressures related to the revolution it had undergone in 1917, signed a treaty with the Germans at the end of that year. The Americans began to mobilize, and their intervention led to Germany's surrender to the Allies in 1918. The German and Austrian-Hungarian empires collapsed, and Germany was forced to bear the brunt of the peace settlements. The experiences of World War I left their mark on European culture, the relationship between governments and national economies, and on international relations. The Treaty of Versailles would prove a failure, as would the League of Nations, founded in hopes of preventing similar conflicts in the future.